U.S. patent application number 12/092730 was filed with the patent office on 2008-10-16 for turning device for turning over sheets in a printing machine.
This patent application is currently assigned to EASTMAN KODAK COMPANY. Invention is credited to Eckhard Bauer.
Application Number | 20080252002 12/092730 |
Document ID | / |
Family ID | 37199161 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080252002 |
Kind Code |
A1 |
Bauer; Eckhard |
October 16, 2008 |
Turning Device for Turning Over Sheets in a Printing Machine
Abstract
The invention relates to a turning device (1) for transporting
and turning over sheets (2) of printing material in a printing
machine, preferably an electrophotographic printing machine, said
device comprising at least two belts (7, 8), which, in particular,
consist essentially of a plastic material, each of said belts being
deflected as closed loops over respectively at least two deflecting
elements (22, 23) and being crossed in order to turn over the
respective sheet by approximately 180 degrees about its axis
pointing in transport direction, in which process said sheet is
held by clamping and frictional engagement between abutting
segments (7', 8') of the tensioned belt, whereby at least one of
the belts (7, 8), preferably each belt, is configured in a
non-elastic manner, specifically reinforced, and that, in order to
tension this belt, a tensioning device is provided.
Inventors: |
Bauer; Eckhard; (Kiel,
DE) |
Correspondence
Address: |
EASTMAN KODAK COMPANY;PATENT LEGAL STAFF
343 STATE STREET
ROCHESTER
NY
14650-2201
US
|
Assignee: |
EASTMAN KODAK COMPANY
ROCHESTER
NY
|
Family ID: |
37199161 |
Appl. No.: |
12/092730 |
Filed: |
September 20, 2006 |
PCT Filed: |
September 20, 2006 |
PCT NO: |
PCT/EP06/09150 |
371 Date: |
May 6, 2008 |
Current U.S.
Class: |
271/277 |
Current CPC
Class: |
B65H 2404/261 20130101;
B65H 15/00 20130101; B65H 2301/33224 20130101; B65H 2301/33212
20130101 |
Class at
Publication: |
271/277 |
International
Class: |
B65H 15/00 20060101
B65H015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2005 |
DE |
10-2005-053-795.2 |
Claims
1. Turning device for transporting and turning over sheets of
printing material in a printing machine, preferably an
electrophotographic printing machine, said device comprising at
least two belts, which, in particular, consist essentially of a
plastic material, each of said belts being deflected as closed
loops over respectively at least two deflecting elements and being
crossed in order to turn over the respective sheet by approximately
180 degrees about its axis pointing in transport direction, in
which process said sheet is held by clamping and frictional
engagement between abutting segments of the tensioned belt,
characterized in that at least one of the belts is configured in a
non-elastic manner, specifically reinforced, and that, in order to
tension this belt, a tensioning device is provided.
2. Turning device as in claim 1, characterized in that the
tensioning device comprises a deflecting element which deflects or
bends the belt.
3. Turning device as in claim 2, characterized in that the
deflecting element is a roller.
4. Turning device as in claim 2 or 3, characterized in that the
deflecting element is subject to a spring bias in tensioning
direction.
5. Turning device as in claim 2, 3 or 4, characterized in that the
belt is deflected essentially in S-form over two deflecting
elements in the region of a tensioning device.
Description
[0001] The invention relates to a turning device for transporting
and turning over sheets of printing material in a printing machine,
preferably an electrophotographic printing machine, said device
comprising at least two belts, which, in particular, consist
essentially of a plastic material, each of said belts being
deflected as closed loops over respectively at least two deflecting
elements and being crossed in order to turn over the respective
sheet by approximately 180 degrees about its axis pointing in
transport direction, in which process said sheet is held by
clamping and frictional engagement between abutting segments of the
tensioned belt.
[0002] Turning devices of the aforementioned type are known from
documents DE 100 23 151 A1 and DE 100 59 913 A1, reference being
made herewith to their entire content.
[0003] For the known turning devices, the belts are tensioned in
that the inherent tension of elastic belts is utilized. With
respect to said belts' inherent elasticity and/or their coefficient
of friction, these belts may essentially behave like rubber.
However, over time, these belts are subject to fatigue and become
loose and age overall, which, over time, impairs the transport and
turning of the sheets.
[0004] Therefore, the object of the invention is to design and
carry out the transport and turning of the sheets more safely and
more reliably, and in an overall more stable manner.
[0005] In accordance with the invention, this object is achieved in
that at least one of the belts, preferably each belt, is configured
in a non-elastic manner, specifically rein-forced, and that, in
order to tension this belt, a tensioning device is provided.
Therefore, in accordance with the invention, the inherent tension
due to the elasticity of the belts used is not available. In
particular, to allow the belt to continue to exhibit rubber-like
behavior on the outside as far as its coefficient of friction is
concerned, the inventive belt is instead preferably reinforced to
make it non-elastic, this potentially being achieved by various
measures, for example, by inserting a core. However, it is also
possible in accordance with the invention to use a jacket and/or a
changed composition of the plastic material that is being used.
[0006] In accordance with the invention, tensioning devices, i.e.,
preferably a separate tensioning device for each belt, are provided
for tensioning or for better tightening the belts. If needed, such
a tensioning device can be readjusted, while the lost inherent
tension of a belt cannot be restored. As a result of the inventive
reinforcement of the belt, said belt can become stiffer, and the
transport can become more reliable and more stable.
[0007] A modification of the invention provides that the tensioning
device comprises a deflecting element which deflects or bends the
belt. Preferably, however not necessarily, this is an additional
deflecting element provided in addition to the minimum of two
deflecting elements, preferably deflecting rollers, which determine
the course of the belt loops. Such an additional deflecting element
can be adjusted in order to control the desired tension, without
changing the actual or main course and the alignment of the belts.
This deflecting element, preferably a roller, can preferably be
moved in a direction approximately transverse to the belt travel
outside the belt segment holding the sheet, and in so doing,
deflects a belt segment more or less severely out of its linear
course and, in so doing, tightens the belt direction or the belt
rotation. In this sense, it is probably better to speak of a
tightening device rather than of a tensioning device.
[0008] Preferably, the deflecting element is (constantly) subjected
to a force of a spring in the tensioning direction, for example, a
helical spring.
[0009] In a modification of the invention, a particularly
accurately adjustable belt tensioning or belt tightening is
possible in that the belt is deflected essentially in S-form over
two deflecting elements in the region of a tensioning device, one
of said deflecting elements preferably being associated with the
actual tensioning device and being movable subject to a spring
force. One embodiment, which could result in additional inventive
features, without, however, restricting the scope of the invention
thereto, is shown by the drawings.
[0010] They show in
[0011] FIG. 1 a perspective view of a turning device of this type
as disclosed by prior art, and
[0012] FIG. 2 a side elevation of a turning device in accordance
with the invention.
[0013] FIG. 1 shows an embodiment of a turning device 1 in
accordance with prior art disclosed by DE 100 59 913 A1.
[0014] A sheet 2, in particular of a printing material, is
transported to the right through the turning device 1 as shown by
the illustration. The transport and turning are achieved by means
of two belts 7, 8, which are arranged in such a manner that two
belt segments 7' and 8' extend in transport direction and, in so
doing, clamp the sheet 2 between them for transport. In this
arrangement, the belts 7, 8 are set at an angle or crossed in such
a manner that, upstream of a crossing region 10, the belt segment
7' is on top and the belt segment 8' is on the bottom, and that,
downstream of the crossing region 10, the belt segment 8' is on top
and the belt segment 7' is on the bottom. As a result of this
crossing of the belts 7, 8, the sheet 2 held between the belt
segments 7', 8' is flipped by 180 degrees about its axis pointing
in transport direction, so that, after the turn-over, the two outer
edges 16, 16' are interchanged, and the former underside is now on
top. The advantage of such a turning device, in contrast with a
turning pocket, for example, is that the same lead edge of the
sheet 2 continues to point in transport direction after said sheet
has been turned over.
[0015] The belts 7, 8 are supported by the deflecting rollers 3, 4,
5 and 6. In this arrangement, the belt 7 is supported by an upper
deflecting roller 3 and by a lower deflecting roller 4. The belt
segment 7' carrying the sheet 2 moves between the underside of the
deflecting roller 3 and the upper side of the deflecting roller 4,
and the returning belt segment 7' moves from the underside of the
deflecting roller 4 to the upper side of the deflecting roller 3.
Correspondingly, the belt segment 8' of the belt 8 moves from the
lower deflecting roller 5 on the top toward the upper deflecting
roller 6 on the bottom, and the returning belt segment 8' of the
belt 8 moves from the upper side of the deflecting roller 6 to the
lower side of the deflecting roller 5. To prevent the returning
belt segments 7' and 8' from rubbing against each other or against
the advancing belt segments 7' and 8', measures have to be taken.
For example, this can be achieved by minimally inclining the
position of the deflecting rollers 3, 4, 5 and 6. To achieve the
aforementioned purpose, it is also possible to use distancing
rollers with collars.
[0016] Inasmuch as, referring to the described turning device 1,
the turning sheet 2 must be held securely by the belt segments 7'
and 8' and must remained aligned while being turned over, it is
suggested that at least three guide rollers 11, 12 and 13 be
provided downstream of the crossing region 10. These guide rollers
11, 12 and 13 are alternately arranged on the belt segments 7' and
8' in such a manner that the belts 7 and 8 are minimally deflected
out of the linear direction, so that the force with which these
belt segments 7' and 8' act on the sheets 2 is increased, this
requiring an inherent elasticity of the belts 7 and 8 that are
used.
[0017] Inasmuch as the turning sheet 2 acts on the belts 7 and 8
with transverse forces, it is suggested that at least one of the
guide rollers 11, 12 and 13 be provided with at least one holding
collar 14. Preferably, the guide rollers 11, 12 and 13 are arranged
in such a manner that two guide rollers 11 and 13 are located in
the upper region and that a lower guide roller 12 is arranged
between them. The second upper guide roller 13 has a holding collar
14 in its rear region, i.e., on side 15, on which the outer edge 16
of the sheet 2 is moved upward downstream of the crossing region
10. In this manner, it is ensured that the absolute positioning and
the relative positions of the belt segments 7' and 8' are
maintained and, in so doing, also the positioning of the relatively
thin sheet 2 is maintained.
[0018] FIG. 1 is a perspective view of the turning device. This
shows how the turning of a sheet 2 in the direction of the arrows
17 takes place. During this process, at the beginning of the
turning device 1, the rear edge 16' moves up, i.e., toward the
zenith, and the front outer edge 16 is down in the crossing region
10. Then, the upper outer edge 16' moves forward and down, and the
lower outer edge 16 moves backward and up, so that, at the end of
the turning device 1, the formerly rear outer edge 16' is in front
and the formerly front outer edge 16 is in back, in which case the
descriptions "back" and "front" are with respect to the viewer of
FIG. 1.
[0019] The turning operation is supported by guiding devices 19, 20
and 21. One guiding device 19 is used for guiding the edge 16' of
the sheet 2, said guiding device 19 starting on side 15, at which
the outer edge 16' of the sheet 2 is moved upward, and then
extending forward in such a manner that the outer edge 16' is
guided up to the end position of the sheet 2, when said sheet
leaves the turning device 1. Only the course of the guiding device
19 has been drawn; for simplification, the mount of said device has
been omitted. It is essential that the guiding device 19 on side 15
extend far enough toward the back and be mounted in such a manner
that the mount does not impair the turning of the sheet 2.
[0020] Another guiding device 20 is used to guide the outer edge 16
which is moved upward downstream of the crossing region 10, until
the sheet 2 has reached the end position. In so doing, the edge 16,
or the area of the sheet 2 adjoining the edge 16, slides upward on
the guiding device 20, until said sheet has reached the horizontal
plane.
[0021] The third guiding device 21 is used to support the edge 16'
toward the end of the turning operation, so that said edge is
prevented from hanging down. To achieve this, the guiding device 21
extends far enough toward the outside that it reaches up to the
edge 16'. It is shown cut off in FIG. 1 in order to not completely
hide the lower deflecting roller 4.
[0022] The embodiment of FIG. 1 also shows that each of the
deflecting rollers 3, 4 and 6 is provided with two holding collars
14 in order to ensure a safe guiding of the belts 7, 8 which are
configured as V-belts.
[0023] In a side elevation, FIG. 2 shows in a much more schematic
and basic manner an embodiment of an inventive turning device based
on a turning device 1 as in FIG. 1. The turning device as in FIG. 2
is not true to scale and shown truncated in its longitudinal
extension.
[0024] The turning device as in FIG. 2 comprises the deflecting
rollers 3, 4, 5 and 6, on which rotate the belts 7, 8 having belt
segments 7', 7'', 8' and 8'. In addition, in accordance with the
invention, the belt segments 7'', 8' are guided over guide rollers
22, 23 and are essentially deflected approximately in an S-form. In
so doing, the guide rollers 22, which can be moved in the
directions of double arrows 24, are subject to the spring bias of
springs 25 in the outward pointing directions 26 of the double
arrows 24. As a result of this, the belts 7, 8, which are
manufactured in accordance with the invention so as to display
essentially no inherent elasticity, are tightened in such a manner
that the guiding belt segments 7', 8' abut against each other in a
taut manner, and securely clamp and transport, as well as turn
over, a sheet located between them.
* * * * *