DEVICE FOR STACKING SHEETS, ESPECIALLY SHEETS OF PAPER OR CARDBOARD TRANSPORTED BY A STREAM FEEDER, ONTO PALLETS

DISPOSITIF D'EMPILAGE DE FEUILLES, EN PARTICULIER DE FEUILLES DE PAPIER OU DE CARTON, TRANSPORTEES PAR MARGEUR A NAPPE, SUR DES PALETTES

English Abstract

In order to stack sheets of paper or cardboard (1) transported by a stream
feeder onto pallets (4), devices are known which comprise a stacking platform
(5) which can be raised and lowered, and on which the piles (3) are formed.
During the stacking process, the longitudinal edge of a sheet (1) is guided by
a separating plate (12) which is suspended on a holding element fixed in the
machine frame, and is connected to a vibrator (13) in the form of a shaking
element. According to the invention, in order to improve the shaking effect of
the separating plate (12), a holding plate (18) is fixed, by means of rubber
elements (19), to the holding element fixed in the machine frame, in such a
way that it is decoupled from vibrations, the separating plate (12) and
vibrator (13) being suspended from the holding plate in a rigid manner.

French Abstract

Pour empiler des feuilles (1) de papier ou de carton transportées par margeur à nappe sur des palettes (4), les dispositifs connus comportent une plate-forme (5) pouvant être levée et abaissée, sur laquelle les piles (3) peuvent être formées. Le bord longitudinal d'une feuille (1) est guidé, lors de l'empilage, par une tôle de séparation (12) suspendue à un support fixé au bâti de machine et reliée à un vibrateur (13) en tant qu'élément d'agitation. Selon la présente invention, pour améliorer l'effet d'agitation de la tôle de séparation (12), une plaque de retenue (18) est fixée par l'intermédiaire d'éléments en caoutchouc (19) de manière à être découplée des vibrations à un support fixé au bâti de machine, la tôle de séparation (12) et un vibrateur (13) étant suspendus de manière rigide à ladite plaque de retenue.

Claims

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Claims
1. A device for stacking sheets (1), especially sheets (1) of paper or
cardboard
transported by a stream feeder, onto pallets (4),
.cndot. with a stacking platform (5) that can be raised or lowered on which
the
stacks (3) are formed, and
.cndot. and with at least one separating plate (12) that guides the
longitudinal edges
of a sheet (1) during the stacking, that is suspended on a holder attached to
the machine frame and with a vibrator (13) as a shaking element,
characterized in that, on the holder attached to the machine frame, there is a
holding plate (18) attached via rubber elements (19) so as to be vibration-
uncou-
pled and on which the separating plate (12) and a vibrator (13) are rigidly
sus-
pended.
2. The device according to Claim 1, characterized in that the separating plate
(12)
is detachably attached to the holding plate (18).
3. The device according to Claim 1 or 2, characterized in that the holder is a
holding plate (14) that is mounted in the machine frame in such a way that it
can
be raised and lowered.
4. The device according to Claim 3, characterized in that an ejection roll
(10) and
a separating shoe (11) are additionally attached to the holding plate (14).

Description

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DESCRIPTION
Device for stacking sheets, especially sheets of paper or cardboard
transported by
a stream feeder, onto pallets
Technical field
The invention relates to a device for stacking sheets, especially sheets of
paper or card-
board transported by a stream feeder, onto pallets, with a stacking platform
that can be
raised or lowered on which the stacks are formed, and with at least one
separating plate
that guides the longitudinal edge of a sheet during the stacking, that is
suspended on a
holder attached to the machine frame and with a vibrator as a shaking element.
State of the art
In order to stack sheets coming from a crosscutting machine, it is a known
procedure to
employ devices having a stacking platform that can be raised or lowered onto
which the
pallets for receiving the stacks have been placed. In the stacking station,
there are stack-
forming elements that ensure trouble-free stacking of the sheets with
precisely aligned
edges. Such stacking mechanisms are in the form of a stop plate for the
leading edges of
the sheets and in the form of separating plates that stand upright and extend
in the sheet-
travel direction while they guide the longitudinal edges of the sheets during
the stacking
operation. The separating plates can be adjusted crosswise to the two
longitudinal sides
of the stacking device and, in the case of a multiple-line stacking operation,
are also
arranged between two stacks that are being formed next to each other. They are
made to
vibrate by means of vibrators so that the stack section being formed is
aligned with pre-

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cise edges. Such stacking devices are described in German patent DE 44 38 964
and in
world patent WO 00/20315.
German patent application DE 29 42 855 A1 discloses a stacking device for a
printing
machine that has vibrating means, each with a linear vibrator, arranged at the
vertical
sides of the paper stack. Each vibrator is elastically suspended by means of a
holding
plate, a rubber block and a holding brace on a stationary frame part of the
stacking
device. Its armature shaft is connected to the vibrating plate.
Another stacking device with vibrating means is described in German patent DE
42 21 660 C2. With this device, a stop plate consisting of two parts is
vibrated, whose
front part is attached to the back part via elastic rubber damping elements.
The vibrating
means is attached to the front part as well as to the back part of the stop
plate.
Description of the invention
The invention is based on the objective of improving the vibrating effect of
the separat-
ing plates in a device of the generic type.
This objective is achieved in that, on the holder attached to the machine
frame, there is a
holding plate attached via rubber elements so as to be vibration-uncoupled and
on which
the separating plate and a vibrator are rigidly suspended.
This construction has the advantage that, during the vibration, the vibrator
itself can
only rest on the stack so that the entire vibration energy is transmitted to
the stack. This
greatly increases the effect of the vibrator.
Another advantage is that the vibrator does not impart vibrations to any other
parts of
the stacking device. Thus, the rest of the suspension of the separating plate
is less
stressed.

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The subclaims contain embodiments of a device according to the invention that
are pre-
ferred since they are especially advantageous:
According to Claim 2, the separating plate is detachably attached to the
holding plate.
Consequently, it can be replaced without disassembling the vibrator.
The embodiment of the holder according to Claim 3 as a holding plate that can
be raised
and lowered makes it possible to raise the separating plate with the vibrator
into an inac-
tive position above the stack when it is not needed.
In the especially advantageous embodiment according to Claim 4, an ejection
roll and a
separating shoe are attached to the holding plate so that all of the stack-
forming ele-
ments that act on a longitudinal edge of the sheet can be raised and lowered
with one
single shared lifting drive.
Brief description of the drawing
The drawing serves to explain the invention with respect to an embodiment
depicted in
a simplified manner:
Figure 1 - is a schematic representation of the side view of a stacking
device.
Figure 2 - is an enlarged representation of the side view of the stack-forming
ele-
ments acting on the longitudinal edges of the sheet.
Figure 3 - is a view of the stack-forming elements opposite from the sheet-
travel
direction.

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Figure 4 - is a schematic view of the suspension of a separating plate with
the
appertaining vibrator.
Ways to execute the invention
The stacking device shown in the figures serves to stack sheets 1 of paper or
cardboard
that are continuously fed by a stream feeder and that were produced with a
crosscutting
machine. The sheets 1 are fed to the stacking station by a feed mechanism 2
that is
configured as a conveyor belt and that is arranged at a fixed vertical
position above the
ground at a height above the maximum stack height. The stacks 3 are formed on
pallets
4 that lie on a stacking platform S. The stacking platform S is suspended in
the frame of
the stacking device so that it can be raised up to the area of the feeding
level of the
sheets 1 and lowered to the floor area.
The frame of the device comprises two inlet-side posts 6 and two outlet-side
posts 7 that
are arranged outside of the working width on the two longitudinal sides of the
machine
and that are connected to each other at their upper ends by longitudinal beams
8 and
transverse beams. The posts 6, 7 define the limits of the stacking station.
In the area of the feeding level of the sheets 1, there are various elements
that serve for a
trouble-free feeding of the sheets 1 to the stacking station and for their
edge-aligned
placement on the stack 3. Up to four stacks 3 are formed next to one another
at the same
time. Therefore, the crosscutting machine additionally cuts the web of paper
or card-
board - from which the sheets 1 are made - into individual webs by making an
appropriate number of longitudinal cuts before the crosscutting operation.
As the stack-forming elements, the device comprises a stop plate 9 extending
crosswise
over the working width of the device, whereby the leading edges of the sheets
are
aligned against said stop. In order to adjust the position of the stop plate 9
in the

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longitudinal direction for different paper lengths, it is suspended so as to
be longitudi-
nally slidable at the rear of the stacking station.
Downstream from the feed mechanism 2, crosswise over the working width, there
are
ejection rolls 10 arranged at a distance from each other, by means of which
the sheets 1
are transferred to the stacking station. In the sheet-travel direction,
immediately down-
stream from the ejection rolls 10, there are separating shoes 11 by means of
which the
longitudinal edges of two adjacent sheets 1 are bent upwards. The curvature of
a sheet 1
along its longitudinal edges leads to so-called cupping, which stabilizes the
sheet 1 and,
at the same time, brings about a reliable separation of two adjacent sheets 1.
Downstream from each separating shoe 11, there is a separating plate 12 that
extends
upright and in the sheet-travel direction. The separating plates 12 have the
function of
laterally guiding and aligning the sheets 1 in order to place them with
precisely aligned
edges on the stack. Therefore, said separating plates are arranged in the
stacking station
between two stacks 3 and on the two outer longitudinal edges of the outer
stack 3. The
separating plates 12 are each suspended on a holder attached to the machine
frame and
connected to a pneumatic or electric motor vibrator 13 that serves as the
shaking drive,
by means of which they are vibrated at a frequency of several Hertz. The
suspension of
a separating plate 12 with a vibrator 13 is shown in greater detail in Figures
2 and 3 and
is depicted schematically in Figure 4:
A separating plate 12 is suspended together with the ejection rolls 10 and the
separating
shoe 11 on a holding plate 14 that serves as a holder and that is attached to
the end of
two guide rails 15. At their upper end, the guide rails 15 are attached to a
carnage 16
that is mounted on a crossbar so as to slide crosswise. A piston-cylinder unit
17, like-
wise attached to the carriage 16 and to the holding plate 14 makes it possible
to raise the
holding plate 14 with the elements attached thereto out of their working
position into an
inactive position above the stack 3. The shared suspension of the ejection
roll 10, of the
separating plate 12 and of the separating shoes 11 has the advantage that
these elements

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can be adjusted crosswise by one single shared traversing drive and they can
be raised
and lowered by a shared lifting drive (piston-cylinder unit 17).
Attached to the holding plate 14, there is a second holding plate 18 that is
arranged in
the front in Figure 2 and to the left of the holding plate 14 in Figure 3. The
second hold-
ing plate 18 is attached to the holding plate 14 exclusively by means of
rubber elements
19 that have a damping effect so that the two holding plates 14, 18 are
vibration-uncou-
pled from each other. As the rubber elements 19, preference is given to the
use of so-
called metal-rubber elements that are rubber-elastic and that have a damping
effect. On
the second holding plate 18, the separating plate 12 and the vibrator 13 are
attached so
as to be suspended rigidly. Due to the vibration-uncoupled attachment of the
second
holding plate 18 to the first holding plate 14 that serves as a holder, the
vibrator 13 can-
not cause the first holding plate 14 to vibrate. The ejection rolls 10 are
attached via a
bearing bracket 20 to this non-vibrating holding plate 14. The separating shoe
11 is con-
nected to the vibrating holding plate 18, so that it is made to vibrate
together with the
separating plate 12. The vibration of the separating shoes 11 causes the
sheets 1 to slide
more easily downwards onto the stack 3.
.~....___._.,~____ ..

Representative Drawing