U.S. patent application number 10/319850 was filed with the patent office on 2003-07-03 for method and device for de-palletizing stacks of blanks.
Invention is credited to Mikulic, Josip, Vogel, Erich.
Application Number | 20030123962 10/319850 |
Document ID | / |
Family ID | 7709628 |
Filed Date | 2003-07-03 |
United States Patent
Application |
20030123962 |
Kind Code |
A1 |
Mikulic, Josip ; et
al. |
July 3, 2003 |
Method and device for de-palletizing stacks of blanks
Abstract
A device for de-palletizing stacks of blanks stacked on pallets
with flat spacing layers disposed in-between, includes a
displaceable gripping head and an insertion tool arranged
approximately horizontally oriented on the gripping head. The
insertion tool is positioned in front of at least one stack of
blanks through displacement of the gripping head for being inserted
with an approximately horizontal movement between the stack of
blanks and the spacing layer for picking up the stack of blanks and
for removing the picked up stack of blanks from the spacing layer
through a displacement of the gripping head. At least one lifting
mechanism is coupled to the gripping head for lifting up one side
of the stack of blanks.
Inventors: |
Mikulic, Josip; (Hamburg,
DE) ; Vogel, Erich; (Escheburg, DE) |
Correspondence
Address: |
VENABLE, BAETJER, HOWARD AND CIVILETTI, LLP
P.O. BOX 34385
WASHINGTON
DC
20043-9998
US
|
Family ID: |
7709628 |
Appl. No.: |
10/319850 |
Filed: |
December 16, 2002 |
Current U.S.
Class: |
414/403 |
Current CPC
Class: |
B65G 61/00 20130101;
B65G 59/04 20130101; B65G 59/023 20130101; B65H 2301/42242
20130101 |
Class at
Publication: |
414/403 |
International
Class: |
B65D 005/14 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2001 |
DE |
101 62 101.9 |
Claims
What is claimed is:
1. A device for de-palletizing stacks of blanks stacked on pallets
with flat spacing layers disposed in-between, comprising: at least
one displaceable gripping head; at least one insertion tool
arranged approximately horizontally oriented on the gripping head
for being positioned in front of at least one stack of blanks
through displacement of the gripping head and for being inserted
with an approximately horizontal movement between the at least one
stack of blanks and the spacing layer for picking up the at least
one stack of blanks, for removing the picked up at least on stack
of blanks from the spacing layer through a displacement of the
gripping head; and at least one lifting means coupled to the
gripping head for lifting up at least one side of the at least one
stack of blanks.
2. The device according to claim 1, including control means for
activating the lifting means before the insertion tool is
inserted.
3. The device according to claim 1, wherein the lifting means is
arranged for being moved vertically.
4. The device according to claim 1, wherein the lifting means on
the gripping head is arranged so that a side of the at least one
stack of blanks facing the insertion tool can be raised.
5. The device according to claim 1, wherein the lifting means
comprises at least one suction element.
6. The device according to claim 6, wherein the suction element is
elastic.
7. The device according to claim 6, wherein the suction element is
a flexible suction cup.
8. The device according to claim 1, forming a combination with the
at least one stack of blanks, and further including at least one
clamping device for clamping the at least one stack of blanks.
9. A method for de-palletizing stacks of blanks, stacked on pallets
with flat spacing layers disposed in-between, comprising the steps
of: positioning at least one approximately horizontally oriented
insertion tool attached to at least one displaceable gripping head
in front of at least one stack of blanks; lifting at least one side
of the at least one stack of blanks; and thereafter inserting the
insertion tool approximately horizontally underneath the at least
one stack of blanks.
10. The method according to claim 9, further including lowering the
at least one stack of blanks following the insertion of the
insertion tool.
11. The method according to claim 9, wherein the lifting step
includes lifting a side of the at least one stack of blanks facing
the insertion tool.
12. The method according to claim 9, including raising and lowering
the at least one stack of blanks with the aid of at least one
suction element.
13. The method according to claim 12, including supplying at least
one of a vacuum and low pressure to the suction element.
14. The method according to claim 12, including deactivating the
suction element once the insertion tool is inserted.
15. The method according to claim 9, including lowering the at
least one stack of blanks onto the insertion tool after the
insertion tool is inserted.
16. A method for de-palletizing stacks of blanks stacked on a
pallet with flat spacing layers disposed in-between, utilizing a
device comprising at least one displaceable gripping head and at
least one horizontally oriented insertion tool that is arranged on
the gripping head and which can be positioned in front of at least
one stack of blanks through a displacement of the gripping head
such that the insertion tool can be inserted with an approximately
horizontal movement between the stack of blanks and the spacing
layer for picking up the at least one stack of blanks and removing
the picked up at least one stack of blanks from the spacing layer
by displacing the gripping head, the method comprising: lifting up
at least one side of the stack of blanks with a lifting mechanism
before the insertion tool is inserted.
17. The method according to claim 16, including moving the lifting
means in vertical direction.
18. The method according to claim 17, including providing a control
unit for controlling the lifting mechanism.
19. The method according to claim 18, including using the lifting
mechanism to lift a side of the at least one stack of blanks that
is facing the insertion tool.
20. The method according to claim 19, including providing the
lifting mechanism in the of at least one suction element.
21. The method according to claim 20, wherein the suction element
is at least one of an elastic and flexible suction cup.
22. The method according to claim 21, including clamping the at
least one stack of blanks with a clamping device.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of German Patent
Application No. 101 62 101.9 filed Dec. 18, 2001. The disclosures
of the foregoing priority application and of each and every U.S.
and foreign patent and patent application mentioned herein, are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a device for de-palletizing stacks
of blanks, stacked on pallets with flat spacing layers disposed
in-between, the device comprising at least one displaceable
gripping head and at least one insertion tool arranged
approximately horizontally oriented on the gripping head. This
insertion tool can be positioned in front of at least one stack of
blanks through displacement of the gripping head and can be
inserted with an approximately horizontal movement between the
stack of blanks and the spacing layer for picking up the stack of
blanks. The tool can remove the picked up stack of blanks from the
spacing layer by displacing the gripping head.
[0003] The invention furthermore relates to a method for
de-palletizing stacks of blanks, stacked on a pallet with flat
spacing layers disposed in-between, for which the at least one
approximately horizontally oriented insertion tool that is attached
to the at least one gripping head is positioned in front of at
least one stack of blanks and is inserted approximately
horizontally underneath the stack of blanks which is removed from
the spacing layer by displacing the gripping head.
[0004] The invention furthermore relates to a method of
de-palletizing stacks of blanks utilizing a device of the type
described above.
[0005] Packaging machines with a high production output process
large amounts of paper blanks or carton blanks. The packaging
material blanks are provided on pallets to ensure a continuous
feeding of packaging material blanks to the machines. The packaging
material blanks are arranged on the pallets in stacks, so as to
form layers, wherein respectively one spacing layer of cardboard or
the like is disposed between the stack layers.
[0006] An insertion tool attached to a gripping head is inserted
between the underside of the respective stack of blanks and the
spacing layer below to remove a stack of blanks from a pallet of
this type. The stack of blanks is lifted up through displacement of
the gripping head and is transferred to a conveying system, which
transports it to the respective packaging machine. To insert the
tool between the stack of blanks to be removed and the spacing
layer, the insertion tool is positioned in front of the stack of
blanks by guiding the gripping head along three axes. Following the
positioning, the insertion tool is inserted between the stack of
blanks and the spacing layer with the aid of a horizontal movement
of the insertion tool. In the process, it can happen that the
insertion tool does not move smoothly into the space between the
stack of blanks and the spacing layer, but is inserted into the
spacing layer instead. When the insertion tool is lifted up, the
spacing layer is also pulled up, so that the remaining stacks of
blanks that are still positioned on the spacing layer are tossed
around and, accordingly, are no longer arranged to enable removal
in an orderly fashion.
[0007] De-palletizing devices and methods of this type are known
from German patent documents DE 37 18 601 A1 and DE 196 53 953 A1,
and European patent document EP 579 031 B1.
[0008] With the de-palletizing device known from DE 37 18 601 A1,
the stack of blanks is deformed by a thrust member acting upon its
top surface, such that a gap is created below the stack on the side
that is assigned to the insertion tongue. The insertion tongue is
inserted into this gap. However, the thrust member also deforms the
stack of blanks.
[0009] EP 579 031 B1 proposes gripping a stack from the side and
lifting it up, wherein any blanks not gripped during the lifting
operation are lifted up with an airflow directed along the side of
the stack from the top toward the support on the bottom. Following
this, the stack is gripped from the top and bottom with the aid of
a so-called clamping tongue and counter-pressure plate.
[0010] In addition, DE 196 53 953 A1 discloses that the spacing
layer is deformed, with the aid of a pressure die, in a region
where the insertion tongue is effective, such that the stack is
fanned out on the side facing the insertion tongue. However, this
hold-down member also causes the stack of blanks, arranged
underneath, to be compressed or even damaged. In addition, gripping
the outer stack of blanks on the pallet is problematic, since no
supporting stack of blanks exists there for the hold-down member.
Thus, the insertion tool can easily be inserted accidentally into
the spacing layer and the outer stack of blanks underneath.
SUMMARY OF THE INVENTION
[0011] It is an object of the present invention to improve the
operation of de-palletizing stacks of blanks, so that the danger of
damage to the spacing layers and the lower blanks in the stacks of
blanks is reduced.
[0012] The above and other objects are accomplished according to
the invention by the provision of a device for de-palletizing
stacks of blanks stacked on pallets with flat spacing layers
disposed in-between, comprising: at least one displaceable gripping
head; at least one insertion tool arranged approximately
horizontally oriented on the gripping head for being positioned in
front of at least one stack of blanks through displacement of the
gripping head and for being inserted with an approximately
horizontal movement between the at least one stack of blanks and
the spacing layer for picking up the at least one stack of blanks,
for removing the picked up at least on stack of blanks from the
spacing layer through a displacement of the gripping head; and at
least one lifting means coupled to the gripping head for lifting up
at least one side of the at least one stack of blanks.
[0013] By lifting the stack of blanks, at least one wedge-shaped
gap is created between the underside of the stack of blanks and the
spacing layer, into which the insertion tool can be inserted.
Lifting up the stack means that no force acts upon the stack so as
to deform it. Furthermore, the relative position of the blanks in
the stack does not change. The stack is lifted with a vertical
movement component. Within the framework of this invention, the
complete stack of blanks and not just one side of the stack can
also be lifted.
[0014] The lifting means can be activated prior to inserting the
tool to make it easier to insert the tool into the gap.
[0015] One advantageous modification of the invention provides that
the lifting means can be moved vertically, in particular
pneumatically. For example, a pressure cylinder can be provided for
guiding the movement of the lifting means, thus making it possible
to reliably carry out exact movements.
[0016] A control and/or regulating unit is advantageously provided
for the lifting means for realizing predetermined movements of the
gripping head and/or the lifting means.
[0017] The lifting means on the gripping head is advantageously
designed so that the side of the stack of blanks facing the
insertion tool can be lifted. As a result, a gap-like opening that
is large enough for inserting the tool forms between the stack of
blanks and the spacing layer. In the process, the insertion tool is
guided so that the spacing layer is not touched or damaged and,
accordingly, stacks of blanks arranged underneath the spacing layer
are also not damaged.
[0018] The lifting means of one preferred embodiment of the
invention is provided with at least one suction element. The
suction element is brought in contact with the stack of blanks to
be picked up before it is lifted up. A vacuum is then supplied to
the suction element, so that the stack of blanks is held by this
suction element during the lifting operation.
[0019] To prevent damage to the stack of blanks, it is advantageous
if the suction element is designed as an elastic and/or flexible
suction cup. In addition, the suction element can thus attach
itself easily to the surface of the stack of blanks.
[0020] According to one preferred modification of the invention, at
least one clamping device is provided for the stack of blanks.
After the stack is picked up, the clamping device can be used for
lifting up the stack of blanks as well as during the displacement
of the gripping head.
[0021] According to another aspect of the invention there is
provided a method for de-palletizing stacks of blanks stacked on
pallets with flat spacing layers disposed in-between, comprising
the steps of: positioning at least one approximately horizontally
oriented insertion tool attached to at least one displaceable
gripping head in front of at least one stack of blanks; lifting at
least one side of the at least one stack of blanks; and thereafter
inserting the insertion tool approximately horizontally underneath
the at least one stack of blanks.
[0022] During the lifting, the stack of blanks itself remains
unchanged and is not deformed. The outer layers of the stack are
not deformed or changed as a result of using the lifting means.
When lifting up the stack and/or only one side of the stack, the
insertion tool can be inserted on the underside of the stack to be
picked up without touching or damaging the spacing layer or
additional stacks.
[0023] The stack of blanks is advantageously lowered once the
insertion tool is inserted underneath the raised stack.
[0024] To achieve a careful and easy handling of the stack of
blanks, it is advantageous if the stack side facing the insertion
tool is raised. A wedge-shaped opening forms as a result between
the underside of the stack and the spacing layer, which offers
sufficient space for inserting the insertion tool.
[0025] The stacks are handled particularly carefully if a suction
element is used to lift and/or lower the stacks of blanks.
[0026] According to one modified version of the invention, it is
advantageous if a vacuum and/or low pressure is generated for the
suction element. The stack adheres well to the suction element if a
low pressure is generated for the suction element once it comes in
contact with the stack to be picked up. Suction cups, for example,
can be used for this because they permit a quick and easy suction
adherence between the stack and the suction cup. In addition, the
adherence can be broken again easily without damaging or deforming
the stack.
[0027] According to one advantageous modification of the invention,
the suction element is deactivated following the insertion of the
insertion tool. As a result, the suction adherence between the
stack and the suction element is broken quickly.
[0028] It is furthermore advantageous if the stack of blanks is
clamped in following the insertion of the insertion tool. As a
result, the stack is held in place firmly on the gripping head, so
that the gripping head can transfer the stack of blanks to a
processing machine, e.g. a cigarette-packaging machine for
producing cigarette packs.
[0029] According to yet a further aspect of the invention there is
provided a method for de-palletizing stacks of blanks stacked on a
pallet with flat spacing layers disposed in-between, utilizing a
device of the type described above, the method including lifting up
at least one side of the stack of blanks with a lifting mechanism
before the insertion tool is inserted.
[0030] The advantageous effects of this lifting can be discerned
from the above explanations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The invention is explained in the following with the aid of
an exemplary embodiment and without restricting the general
inventive idea.
[0032] FIG. 1 is a perspective view of a pallet loaded with stacks
of blanks.
[0033] FIGS. 2a-2c are views from the side of an exemplary
embodiment of the device according to the invention in different
positions based on the method according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Identical or corresponding parts are given the same
reference numerals in the drawings and will not be introduced
again.
[0035] FIG. 1 shows a pallet 1 having a supply of blank stacks 2
stacked thereon. Spacing layers 3 for stabilizing the stack
configuration on the pallet 1 are arranged between the various
layers containing stacks of blanks 2.
[0036] FIGS. 2a to 2c respectively show different operating
positions of a gripping head 4 for a de-palletizing device, for
example as represented in FIGS. 2 and 3 of German Patent Document
DE 196 53 953 A1. The gripping head 4 is provided with a horizontal
guiding device 6 for example, a pressure cylinder, which comprises
a horizontally displaceable guide rod 12 with a vertical guide
element 13 attached to its free end. An insertion tool 5 is
arranged at the lower end of the guide element 13, which is
provided with a sharp insertion edge on the front. The insertion
tool 5 is designed as a flat tongue and extends downward at a
slight angle to the horizontal line. Thus, its insertion edge is
driven and guided vertically displaceable by moving the gripping
head 4 or the guide element 13 in a downward direction.
[0037] The guiding device 6 and the guide rod 12 can be designed as
pneumatic or hydraulic piston-cylinder units. For an exact
positioning, however, the guide rod 13 in the guiding device 6 can
also be operated with an electric motor.
[0038] For the de-palletizing operation, the gripping head 4 is
positioned in front of a stack of blanks 2 containing a
predetermined number of blanks. The stack of blanks 2 is held
together in the center with a closing band 7. The closing band 7
also protects against dirt. On the whole, the stack of blanks 2 is
shaped like a package.
[0039] The insertion tool 5 is positioned opposite a side 11 of the
stack of blanks 2 positioned on the spacing layer 3.
[0040] The gripping head 4 is provided with a hold-down member 8,
which is arranged in the area of side 11 that is assigned to the
insertion tool 5 when the gripping head 4 is positioned in front of
the stack of blanks 2. The hold-down member 8 can be moved
vertically via a guide rod 17 and by means of a pressure cylinder
9. The pressure cylinder 9 is connected to a control unit 18 or,
alternatively, to a regulating unit, so that the guide rod 17 can
be moved precisely with the pressure cylinder 9.
[0041] A vertically guided suction cup 10 is furthermore attached
to the guide rod 17 of the hold-down member 8, next to the
hold-down member 8. The suction cup 10 has an elastic and flexible
design and consists, for example, of rubber or a rubber-type
material. The suction cup is connected via a low-pressure line 15
to a low-pressure source 16 and can be subjected to low
pressure.
[0042] FIG. 2a shows the starting situation before the stack 2 is
removed from the spacing layer 3. Following the positioning of the
gripping head 4 in front of the stack 2, the pneumatic hold-down
member 8 is lowered. The suction cup 10 is lowered at the same time
as the hold-down member 8. The open underside of the suction cup 10
comes to rest on the closing band 7 of stack 2 before the hold-down
member 8 touches the surface of stack 2. In this position, the
vertical downward movement of the hold-down member 8 and the
suction cup 10 is stopped. A low pressure is subsequently applied
to the suction cup 10, so that the stack 2 is subsequently gripped
at the closing band 7 (FIG. 2b).
[0043] By moving the suction cup 10 upward with the aid of pressure
cylinder 9, the stack 2 is lifted up vertically on one side, so
that a gap 14 forms between the underside of stack 2 and the
spacing layer 3. The gap 14 is wedge-shaped as a result of lifting
up only one side of the stack of blanks 2, wherein the height of
this gap 14 is sufficient for inserting the insertion tool 5 into
the gap 14.
[0044] Of course, the stack of blanks 2 can be lifted up completely
with a differently positioned suction element, e.g. if the suction
element is arranged near or above the center of gravity for the
stack 2.
[0045] Once the insertion tool 5 is inserted into the gap 14 (FIG.
2c), the hold-down member 8 and the suction cup 10 are lowered
further. As soon as the insertion tool 5 is inserted completely
into the gap 14, the low pressure supplied to the suction cup 10 is
turned off. Following this, the hold-down member 8 can be raised
once more. The stack 2 positioned on the insertion tool 5 can be
conveyed further and transferred with the aid of gripping head 4 to
a machine for further processing, for example a cigarette packaging
machine for producing cigarette packs.
[0046] The subject matter of this invention prevents the insertion
tool on the gripping head 4 from damaging the spacing layer 3 or
any other stacks positioned underneath it. In particular, the
invention is utilized for stacks 2 that are provided with closing
bands and are extremely stiff. The invention particularly makes use
of the fact that the stacks of blanks 2 with closing bands cannot
be deformed. Existing gripping heads 4 can therefore be retrofitted
easily with a lifting means 10, in particular a suction cup.
[0047] The invention has been described in detail with respect to
preferred embodiments, and it will now be apparent from the
foregoing to those skilled in the art, that changes and
modifications may be made without departing from the invention in
its broader aspects, and the invention, therefore, as defined in
the appended claims, is intended to cover all such changes and
modifications that fall within the true spirit of the
invention.
* * * * *