[0001] The present invention relates to a method for extracting intermediate flat supports
for stacks of products.
[0002] In particular, the invention relates to a method for extracting intermediate flat
supports for stacks of cardboard cutouts arranged on pallets and the like.
[0003] Devices are currently known which allow to pick up stacks of cutouts, such as for
example those used to package cigarette packets of the rigid flip-top type. These
stacks of cutouts are generally arranged on a pallet-like support in multiple rows
and in a plurality of layers that are separated from one another, in pairs, by an
intermediate flat support constituted for example by a sheet of paper of appropriate
thickness.
[0004] These devices pick up the stacks of cutouts in an orderly fashion and then transfer
them to an inlet of a user machine.
[0005] Once the transfer of an entire layer of stacks of cutouts has been completed, the
intermediate flat support is extracted.
[0006] For this purpose, there are provided appropriate devices which have means for gripping
said intermediate flat support and are constituted for example by sucker-fitted suction
means.
[0007] Said grip means are capable of moving between a position for picking up the intermediate
flat supports and a position for releasing said intermediate flat supports inside
a collecting container.
[0008] In known extraction devices, in many cases the cutouts arranged at the top of the
stacks of the layer that lies below the flat support to be extracted cling to said
flat support when it is picked up by said sucker-fitted suction means.
[0009] Due to the porosity of the material that constitutes the flat support, the suction
of the suckers also affects the cutouts arranged at the regions where said suckers
are applied.
[0010] Furthermore, more generally, the lifting of the flat support tends to produce, with
known extraction devices, a movement of the cutouts located at the top of the stacks
with respect to the lower ones, due to adhesion between said flat support and said
cutouts.
[0011] A principal aim of the present invention is to provide an extraction method that
allows to eliminate the above-described drawback, extracting the intermediate flat
supports without interfering with the stacks of products.
[0012] According to the present invention, a method is provided for extracting intermediate
flat supports of stacks of products, characterized in that it comprises the steps
of: moving a grip element above a flat support to be extracted; activating presser
means, carried by said grip element, to act on the stacks lying below said flat support,
by virtue of the interposition of said flat support; lifting said flat support, at
its peripheral region, by virtue of suction means carried by said grip element, and
deactivating said presser means; and moving said grip element to place said grip element
at means for collecting said extracted flat support.
[0013] Preferably, the step of moving said element above said flat support to be extracted
is performed by moving said suction means into contact with said flat support.
[0014] The invention is now described with reference to the accompanying drawing, which
illustrates a non-limitative embodiment thereof, in which the only figure is a schematic
side view of an extraction device that performs the method according to the present
invention.
[0015] With reference to the above figure, the reference numeral 1 designates a device for
extracting intermediate flat supports 2 for stacks 3 of cutouts, such as for example
those used to package cigarette packets of the rigid type.
[0016] The stacks 3 of cutouts are arranged in an orderly fashion on pallet-like supporting
means 4. In particular, the stacks 3 of cutouts are arranged so as to form superimposed
layers 5 that are separated from one another by virtue of the intermediate flat supports
2, which are made of flexible material, for example paper.
[0017] The extraction device 1 includes a vertical framework 6 provided with a container
7 for collecting the extracted flat supports 2. Said framework 6 is provided, in a
substantially median position, with a bracket 8, and an arm 10 which oscillates on
a vertical plane is pivoted to said bracket 8 by means of a pivot 9 having a horizontal
axis. The arm 10 is actuatable, by means of a crank 11, by a jack 12 that is pivoted
to said framework 6.
[0018] A grip element 14 is articulated to the free end of the oscillating arm 10 by means
of a pivot 13 having a horizontal axis. Said grip element 14 comprises a frame 15
provided with suction means 16 that are constituted for example by a plurality of
suckers 16 adapted to be connected to appropriate known suction devices, which are
not shown in the figure. The grip element 14 is furthermore provided, on the same
side as the suckers 16, with a plurality of presser elements 17 that are actuatable
by respective actuators 18 along axes that are perpendicular to the frame 15.
[0019] The suckers 16 are arranged at opposite ends of the frame 15, so as to act at the
peripheral region of the flat support 2 to be extracted, while the pressers 17 are
arranged in a central region of said frame 15.
[0020] The method for extracting the intermediate flat supports 2 entails a first step during
which, by rotating the oscillating arm 10, actuated by the jack 12, the frame 15 is
placed above the flat support 2 to be extracted so that the suckers 16 are arranged
in contact with said flat support 2.
[0021] It should be pointed out that for the sake of clarity said first step is shown in
the accompanying figure with the frame 15 arranged (dashed line) above a flat support
2 that separates two lower layers 5 of stacks 3.
[0022] Thereafter the presser elements 17 are actuated by the actuators 18. Said pressers
17 act on the stacks 3 that lie below the flat support 2 to be extracted, by virtue
of the interposition of said flat support 2, in order to apply a constant pressure
that is directed towards the pallet 4 and is capable of blocking said stacks 3.
[0023] Then, first the suction means connected to the suckers 16 are activated and thereafter
an upward rotation of the arm 10 is actuated the extent whereof is such as to cause
a slight lifting of the frame 15 and accordingly a slight curving of the flat support
2, the peripheral region whereof is raised with respect to the cutouts that constitute
the top of the stack 3. This step of the operation of the device 1 is shown (in solid
lines) in the upper part of the figure, with reference to the removal of the upper
flat support 2.
[0024] The subsequent deactivation of the actuators 18 that actuate the pressers 17 allows
the flat support 2 to fully separate from the stacks 3 and to continue to be retained
against the frame 15 by means of the suckers 16, preventing relative movements of
the cutouts that lie below said flat support 2.
[0025] Finally, the rotation of the oscillating arm 10 is completed, and said arm is arranged
in a vertical position (dot-and-dash line), while known actuators, not shown, are
actuated to turn the frame 15 about the pivot 13 and move said frame 15 into a vertical
position (dot-and-dash line) at the container 7, inside which the extracted flat support
2 is allowed to drop as a consequence of the deactivation of said suction means.
[0026] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. A method for extracting intermediate flat supports (2) of stacks (3) of products,
characterized in that it comprises the steps of: moving a grip element (14) above
a flat support (2) to be extracted; activating presser means (17), carried by said
grip element (14), to act on the stacks (3) that lie below said flat support (2),
with said flat support (2) being interposed; lifting said flat support (2), at its
peripheral region, by virtue of suction means (16) carried by said grip element (14),
and deactivating said presser means (17); and moving said grip element (14) to place
said grip element (14) at means (7) for collecting said extracted flat support (2).
2. Method according to claim 1, characterized in that said step of placing said grip
element (14) above said flat support (2) to be extracted is performed by moving said
suction means (16) into contact with said flat support (2).