[0001] The present invention relates to a transfer device for sheet products, such as tissues,
napkins and the like.
[0002] The production lines of paper-like products, such as tissues, napkins and the like,
of all sizes, are usually provided, predominantly in the final steps of the production
process, with at least one drum, which rotates about its own axis and is provided
internally with elements for providing a partial vacuum of appropriate value: said
partial vacuum is adapted to retain, by way of appropriately provided openings, the
products so that they adhere to its outer surface, so as to perform, in association
with other elements, one or more folds according to a predefined order or in any case
other final operations of the process.
[0003] The products which adhere to the outer surface of the drum are usually then picked
up by belt assemblies which convey them, on their upper portions, toward a station
for stacking the products on each other for packaging in packs, said station usually
comprising at least one star conveyor whose rotation axis is parallel to the rotation
axis of the drum and which is provided with a plurality of peripheral receptacles
in which the products are inserted and from which they are then deposited one by one
on a movable supporting surface, which forms the stack which will then be packaged
in a pack.
[0004] The need is currently felt, for many reasons, to eliminate the step of conveying
the products by means of the belt assemblies. First of all, the need is in fact felt
to make production lines cheaper and constructively simpler; secondly, the need is
felt to increase the transfer rate of the products from the drum to the star conveyor.
[0005] The aim of the present invention is to meet the mentioned requirements, by providing
a transfer device for tissues, napkins and the like which allows to convey the products
directly from the partial vacuum drum to the stacking star conveyor without the need
for intermediate conveyor assemblies.
[0006] Within this aim, an object of the present invention is to provide a device having
a structure which is simple, relatively easy to provide in practice, safe in use,
effective in operation, and has a relatively low cost.
[0007] This aim and these and other objects which will become better apparent hereinafter
are achieved by the present transfer device for sheet products such as tissues, napkins
and the like, which comprises at least one drum which rotates about its own axis and
is provided with retention means which are adapted to retain products such as tissues,
napkins and the like so that they adhere to its outer surface along at least one portion
of its rotation, and at least one star conveyor which is affected peripherally by
a plurality of receptacles for the insertion of the products and for the release of
said products at subsequent production stations, characterized in that it comprises
at least one element for rotationally entraining the products one by one, which is
arranged substantially between said drum and said star conveyor and is adapted to
follow the insertion of each product within said receptacles.
[0008] Further characteristics and advantages of the invention will become better apparent
from the following detailed description of a preferred but not exclusive embodiment
of a transfer device for tissues, napkins and the like according to the invention,
illustrated by way of non-limiting example in the accompanying drawings, wherein:
Figure 1 is a perspective view of a transfer device according to the invention;
Figure 2 is a side elevation view of the device;
Figure 3 is a detail view of Figure 2;
Figure 4 is a front view of the device;
Figure 5 is a bottom view of the device.
[0009] In the exemplary embodiment that follows, individual characteristics may actually
be interchanged with other different characteristics that exist in other exemplary
embodiments.
[0010] Moreover, it is noted that anything found to be already known during the patenting
process is understood not to be claimed and to be the subject of a disclaimer.
[0011] With reference to Figure 1, the reference numeral 1 generally designates a transfer
device for sheet products, such as tissues, napkins and the like according to the
invention.
[0012] The device 1 is extremely versatile and is absolutely general in its application,
since it can be used in production lines of tissues, napkins and the like having the
most disparate characteristics.
[0013] The products 2 processed by the device according to the invention can be constituted
by tissues, napkins and the like of various sizes, with any arrangement of folds and
with any number of plies. The materials of which said products are made also may be
any, although usually they are paper-like or similar materials.
[0014] The device comprises advantageously a drum, generally designated by the reference
numeral 3, which rotates about its own axis and is associated with means for rotary
actuation and is supported in fixed portions of the production line. For the sake
of simplicity in understanding, the means for the rotary actuation of the drum and
the fixed parts of the production line are not shown in the figures but are however
of a substantially known and traditional type.
[0015] The rotating drum 3 is provided with retention means, generally designated by the
reference numeral 4, which are adapted to retain the products 2 so that they adhere
to the outer surface 5 of the drum 3 along at least one portion of their rotation,
as will become better apparent hereinafter.
[0016] The device further comprises a star conveyor, generally designated by the reference
numeral 6, which is affected peripherally by a plurality of receptacles 7 for the
insertion of the products 2 conveyed by the drum 3 and is also adapted for releasing
the products 2, accommodated in the receptacles 7, at subsequent production stations.
Said production stations are constituted generally by at least one station for stacking
the products 2 on each other so that they can be then packaged in packs.
[0017] The device further comprises advantageously at least one element 8 for rotationally
entraining the products 2 one by one, which is arranged substantially between the
drum 3 and the star conveyor 6 and is supported by fixed parts of said device: the
entrainment element 8 advantageously allows to achieve the guided following of each
of the products 2 in their insertion within the receptacles 7.
[0018] The star conveyor 6 comprises at least one pair of mutually opposite flat and parallel
disks 9, 10, each of which is affected by respective receptacles 7 which are mutually
angularly equidistant and have an inlet portion which has a larger cross-section in
order to facilitate the insertion of the products 2; the disks 9, 10 are rigidly keyed
along a same actuation shaft 11. The entrainment element 8 is preferably arranged
in the space comprised between the disks 9, 10.
[0019] The rotary entrainment element 8 is constituted preferably by at least one head,
which is made of a material which has a high friction coefficient for the products,
for example rubber or the like.
[0020] The head of the entrainment element 8 can be for example substantially cylindrical
(Figure 3), so as to determine contact with the drum 3 along the respective generatrices,
or can have any other geometry suitable for this purpose.
[0021] The retention means 4 for retaining the products on the outer surface 5 of the drum
3 are of the type, i.e. comprise apparatus, adapted to create an appropriate partial
vacuum within said drum, such as to retain the products 2 which adhere to the outer
surface 5: said apparatus of the retention means comprise for example a circuit which
is connected to a vacuum pump which is connected to openings formed along the outer
surface 5 of the drum 3.
[0022] The outer surface 5 of the drum 3 is affected preferably by, i.e. has formed thereon,
at least one pair of circumferential grooves 12, 13, within which the peripheral edges
14 of the disks 9, 10 engage, so as to create a sort of interpenetration between the
star conveyor 6 and the drum 3, facilitating the insertion of the products 2 in the
receptacles 7.
[0023] The operation of the transfer device according to the invention is intuitive. The
products 2, which arrive from other production stations (for example the folding stations
and others) are retained one by one by adhesion to the outer surface 5 of the drum
3, which by rotating (for example counterclockwise in Figure 2) conveys said products
at the region of interpenetration with the star conveyor 6. The retention means 4,
by way of the action of appropriately provided valves formed in the partial vacuum
circuit, release the products 2, which are therefore followed, substantially at the
same peripheral speed as the drum 3, by the rotary entrainment element 8 so as to
enter the receptacle 7.
[0024] The products 2 loaded in the star conveyor 6 are then deposited at a subsequent production
station, for example the station for stacking said products on each other, and are
then packaged.
[0025] It has thus been shown that the invention achieves the intended aim and objects.
[0026] The transfer device according to the invention allows to perform transfer from the
drum to the star effectively and reliably, without the presence of belt conveyance
means and the like, which are often expensive and have an excessively limited production
capacity.
[0027] The invention thus conceived is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims.
[0028] All the details may further be replaced with other technically equivalent ones.
[0029] The embodiment of the present invention shall be carried out in the most scrupulous
compliance with the statutory and regulatory provisions related to the products of
the invention or correlated thereto and following any required authorization of the
corresponding competent authorities, with particular reference to regulations related
to safety, environmental pollution and health.
[0030] In practice, the materials used, as well as the shapes and the dimensions, may be
any according to requirements without thereby abandoning the scope of the protection
of the appended claims.
[0032] 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 transfer device for sheet products, such as tissues, napkins and the like, comprising
at least one drum (3) which rotates about its own axis and is provided with retention
means (4) which are suitable to retain products (2) such as tissues, napkins and the
like so that they adhere to its outer surface (5) along at least one portion of its
rotation, and at least one star conveyor (6) which is affected peripherally by a plurality
of receptacles (7) for the insertion of the products (2) and for the release of said
products (2) at subsequent production stations, characterized in that it comprises at least one element (8) for rotationally entraining the products one
by one, which is arranged substantially between said drum (3) and said star conveyor
(6) and is adapted to follow the insertion of each of the products (2) within said
receptacles (7).
2. The device according to claim 1, characterized in that said star conveyor (6) comprises at least one pair of flat disks (9, 10) which are
mutually parallel and opposite and are each affected by said receptacles (7) and rigidly
keyed along a same actuation shaft (11), said rotary entrainment element (8) being
arranged between said disks.
3. The device according to claims 1 and 2, characterized in that said rotary entrainment element (8) comprises at least one head, which is made of
a material having a high friction coefficient with respect to the products (2) and
is supported in fixed parts of said device.
4. The device according to one or more of the preceding claims, characterized in that said retention means (4) are of the type adapted to produce a partial vacuum within
said drum (3) and are connected to openings formed in said outer surface (5).
5. The device according to one or more of the preceding claims, characterized in that said outer surface (5) of said drum (3) is affected by at least one pair of circumferential
grooves (12, 13), within which the peripheral edges (14) of said disks (9, 10) engage.