U.S. patent application number 10/677437 was filed with the patent office on 2004-07-01 for device for transporting and aligning stacks of sheet-shaped print materials.
Invention is credited to Freund, Michael, Hirsch, Alexander, Mauz, Harald, Rieger, Albert, Wurschum, Hans-Peter.
Application Number | 20040126219 10/677437 |
Document ID | / |
Family ID | 32010127 |
Filed Date | 2004-07-01 |
United States Patent
Application |
20040126219 |
Kind Code |
A1 |
Mauz, Harald ; et
al. |
July 1, 2004 |
Device for transporting and aligning stacks of sheet-shaped print
materials
Abstract
The invention relates to a device for transporting and centrally
aligning stacks of sheet-shaped materials. According various
aspects of the invention, methods and devices are provided for
transporting stacks of sheet-shaped print materials in a transport
from a location misaligned with a reference axis to another
location while aligning a center of a stack thickness with the
reference axis.
Inventors: |
Mauz, Harald; (Ehingen,
DE) ; Freund, Michael; (Adelberg, DE) ;
Hirsch, Alexander; (Kirchheim, DE) ; Rieger,
Albert; (Geislingen, DE) ; Wurschum, Hans-Peter;
(Ostfildern, DE) |
Correspondence
Address: |
Kevin L. Leffel
Heidelberg Digital L.L.C.
2600 Manitou Road
Rochester
NY
14624
US
|
Family ID: |
32010127 |
Appl. No.: |
10/677437 |
Filed: |
October 2, 2003 |
Current U.S.
Class: |
414/790.2 |
Current CPC
Class: |
B42C 19/08 20130101;
B42P 2261/04 20130101 |
Class at
Publication: |
414/790.2 |
International
Class: |
B65H 031/30 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 2, 2002 |
DE |
102 46 073.6 |
Claims
We claim:
1. A method, comprising: transporting stacks of sheet-shaped print
materials in a transport from a location misaligned with a
reference axis to another location while automatically aligning a
center of a stack thickness with the reference axis.
2. The method of claim 1, comprising aligning the stack of
sheet-shaped print materials independently of the stack
thickness.
3. The method of claim 1, wherein the stacks of sheet-shaped print
materials are unbound.
4. The method of claim 1, comprising securely moving the stack of
sheet-shaped print materials from the first location to the second
location.
5. The method of claim 1, comprising securely moving the stack of
sheet-shaped print materials collected at a fixed stop to another
processing station.
6. The method of claim 1, wherein at the second location one-half
of the thickness of the stack of sheet-shaped print materials is
disposed on one side of the reference axis and another one-half of
the thickness of the stack of sheet-shaped print materials is
disposed on another side of the reference axis.
7. The method of claim 1, comprising a carriage in the transport
and having a first clamping jaw and a second clamping jaw for
gripping the stack of sheet-shaped print material; and comprising
always centering the carriage between the first clamping jaw and
the second clamping jaw.
8. The method of claim 1, the device (100) takes the stack of
sheet-shaped print materials (1) from a collecting device for
sheet-shaped print materials.
9. An apparatus, comprising: a transport defining a transport path;
a carriage carried in the transport and having a first clamping jaw
and a second clamping jaw for gripping a stack of sheet-shaped
print material; a guide along the transport path which guides the
carriage from a location wherein the stack of sheet-shaped print
material is misaligned with a reference axis to another location
wherein a center of a stack thickness is aligned with the reference
axis.
10. The device of claim 9, wherein the guide is shaped to guide the
carriage from the location wherein the stack of sheet-shaped print
material is misaligned with the reference axis to the another
location wherein the center of the stack thickness is aligned with
the reference axis.
11. The device of claim 9, wherein the first clamping jaw and
second clamping jaw are oriented to clamp the sheet-shaped print
materials vertically between the clamping jaws.
12. The device of claim 9, wherein the first clamping jaw and the
second clamping jaw are mutually linked to the carriage by way of a
parallelogram.
13. The device of claim 9, wherein the first clamping jaw and the
second clamping jaw are mutually linked to the carriage by way of a
parallelogram configured to always place the carriage centered
between the first clamping jaw and the second clamping jaw.
14. The device of claim 9, wherein the first and second clamping
jaws are mutually linked to the carriage by way of a
parallelogram., the transport is open on both sides of the stack of
sheet-shaped print materials.
15. The device of claim 9, wherein the first clamping jaw and the
second clamping jaw are mutually linked to the carriage by way of a
parallelogram, at least one of the clamping jaws being mounted in
such that the clamping jaws adapt to stacks of sheet-shaped print
materials that do not have uniform thickness.
16. The device of claim 9, comprising a measuring device that
measures the stack thickness.
17. The device of claim 9, comprising a protective device that can
switch off a clamping movement of the first clamping jaw and the
second clamping jaw.
18. A method, comprising: transporting unbound stacks of
sheet-shaped print materials in a transport from a location
misaligned with a reference axis to another location while
automatically aligning a center of a stack thickness with the
reference axis, wherein at the second location one-half of the
thickness of the stack of sheet-shaped print materials is disposed
on one side of the reference axis and another one-half of the
thickness of the stack of sheet-shaped print materials is disposed
on another side of the reference axis.
19. The method of claim 1, comprising a carriage in the transport
and having a first clamping jaw and a second clamping jaw for
gripping the stack of sheet-shaped print material; and comprising
always centering the carriage between the first clamping jaw and
the second clamping jaw.
20. The method of claim 1, the device (100) takes the stack of
sheet-shaped print materials (1) from a collecting device for
sheet-shaped print materials.
Description
BACKGROUND
[0001] The invention relates to a device for transporting and
centrally aligning stacks of sheet-shaped print materials.
[0002] Typically, devices of the type named are used to move stacks
of sheet-shaped materials, which will be bound or are already
bound, from one processing station to the next in a print further
processing device. What is important is that the sheet-shaped
materials in the stack do not lose their alignment with respect to
each other since otherwise errors would occur during the outside
edge processing of the stack of sheet-shaped materials. Another
error that could otherwise occur is that punched holes, e.g. for a
wire comb binding, plastic comb binding or spiral binding, can
slip, which leads to later problems when a corresponding binding
element is threaded through.
[0003] In many applications for binding stacks of sheet-shaped
materials, it is necessary to guide the stack of sheet-shaped
materials in a specific alignment through a corresponding device in
order to ensure precise processing of the stack of sheet-shaped
materials at different stations. This is especially the case if, in
a digital printing machine, the individual pages of a print order
are printed individually in sequence and then collected into the
stack of sheet-shaped materials, which will be bound into a
brochure or a book after that. In this process, the individual
sheet-shaped materials that make up the stack are automatically
collected against a stop. Usually this stop represents a more or
less horizontal tray surface on which the individual pages are
collected, but trays for vertical sheet-shaped materials are also
known. Alternatively, devices are known that swing a stack of
sheet-shaped materials from the horizontal position into a vertical
position in order to make the stack available in this way for
further processing stations.
[0004] Different print orders now generally comprise a different
number of printed pages. Because of this, generally there are
stacks of sheet-shaped print materials of different thicknesses. If
these stacks of sheet-shaped print materials are then to be aligned
symmetrically to the stack thickness for the subsequent processing
procedures, each stack must be aligned according to its thickness,
i.e. an offset of the position of half the stack thickness of such
a stack would be necessary, which depends on the number of pages in
a print order.
[0005] Devices for transporting vertically aligned stacks of
sheet-shaped materials are known from the state of the art. So, for
example, the German OLS DE 22 26 455 shows a device for producing
books from single-knife book binding machines. This device provides
for transporting books from a single-knife book binding machine on
a conveyor belt whereby at no point in the conveyor path is the
book left unattended and especially does not cover distances in
free fall. To do this, among other things two grippers are provided
that grip the book on the cover on both sides. Thus, it is a case
of transporting books that are already bound.
[0006] Another conveyor device for book binding machines is
disclosed in the German OLS DE 199 26 407. The device shown there
relates to plate conveyors or studded chains or comparable
conveying means in which the spacing between the chain bars of the
studded chain is carried out automatically for the purpose of
adapting to different book block thicknesses. In this process, the
chain bars are linked to each other via a motor-driven
double-threaded spindle. Because of this, the chain bars move,
towards each other or away from each other, symmetrically with
respect to the center of the book blocks. The book block thickness
is determined by a measuring device during the setup operation and
sent to the actuating elements as a reference. No alignment of the
center of the book blocks relative to the transport path takes
place.
[0007] Another device for transferring book blocks to transport
means of a book binding machine is found in the German OLS DE 100
45 401. Here as well, the book block is held on both sides by
clamping elements. In addition, the device shown there makes it
possible to align at least one corner of the spine of a book block
held with frictional connection by relative displacement of the two
sides of the book block in the plane of the book block into a
defined position.
SUMMARY
[0008] According various aspects of the invention, methods and
devices are provided for transporting stacks of sheet-shaped print
materials in a transport from a location misaligned with a
reference axis to another location while aligning a center of a
stack thickness with the reference axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 presents a schematic representation of a device
according to an aspect of the invention in a starting position, and
parts of a device from which the device according to an aspect of
the invention takes the stack of sheet-shaped materials.
[0010] FIG. 2 presents a schematic representation of the FIG. 1
device when it is at half run-out, as well as parts of the device
from which the FIG. 1 device takes the stack of sheet-shaped
materials.
[0011] FIG. 3 presents a schematic end view of the FIG. 1 device in
a run-out position in contact with the stack of sheet-shaped
materials on one side.
[0012] FIG. 4 presents a schematic end view of the FIG. 1 device in
a run-out position in contact with the stack of sheet-shaped
materials on both sides.
[0013] FIG. 5 presents a schematic end view of the FIG. 1 device in
a starting position with a stack of sheet-shaped materials aligned
centrally.
DETAILED DESCRIPTION
[0014] Various aspects of the invention are now presented with
reference to FIGS. 15, which are not drawn to any particular scale,
and wherein like components in the numerous views are numbered
alike. Generally known drive and/or guiding means, cams or
electronic elements required for operating the devices described
herein are shown only schematically and/or are only described in a
general way. Referring now to FIG. 1, a stack of sheet-shaped
materials 1 with a stack thickness D and a center line MB of the
stack of sheet-shaped materials is held by a collecting device 2,
which is only partially shown, for providing stacks of sheet-shaped
materials in vertical position. This device 2 for providing stacks
of sheet-shaped materials 1 may be e.g. a collecting device for
sheet-shaped materials. In such a collecting device 2, typically
the sheet-shaped materials are collected horizontally on a tray
surface and then if necessary tipped into a vertical position using
a suitable tong apparatus. The stack of sheet-shaped materials 1 is
in contact here with the tong element 10. Below the tong element
10, there is a bracket guide 12 for the clamping jaws 20.
Alternatively, it could also be another guide known to the person
skilled in the art.
[0015] FIG. 1 shows a device 100 according to an aspect of the
invention in its starting position. Here clamping jaws 20, 20' are
located in the area of a tray surface 50, which is part of a
vibrating table. The vibrating table has a drive marked with a
reference character 52. The clamping jaws 20, 20' are each mounted
on a tong body 24, 24'. The clamping jaws 20, 20' and the tong
bodies 24, 24' are connected to a carriage 30 (see FIG. 3). The
carriage 30 can be moved by a drive 46, by means of tong carriers
42, 42', along the sliding rails 47, 47' in a transport direction.
The carriage 30 is also guided laterally with respect to a
transport direction. The position of the tong carriers 42, 42' is
controlled, among other things, by an optical switch 48 (see FIG.
2). A first clamping jaw 20 has an upper guide mandrel 22, on the
tip of which a running wheel 23 is mounted (see FIG. 3).
[0016] FIG. 2 shows the carriage 30 when it is half run out, just
before the upper guide mandrel 22 moves, along with the running
wheel 23, into the bracket guide 12. The carriage 30 has on its
underside a second lower guide mandrel 33 that is in contact with a
bracket guide 44, 44'. The bracket guide 44' tracks laterally
toward the first clamping jaw 20 (to the left in FIG. 2) so that
further movement of the device 100 presses the carriage 30
laterally in the direction of the first clamping jaw 20, until the
running wheel 23 is aligned with the bracket guide 12. As soon as
the guide mandrel 22 is in contact with the bracket guide 12 of the
clamping jaw 20, the lower guide mandrel 33 is released from the
bracket guide 44. Furthermore, at this point, the distance between
the clamping jaws 20, 20' is maximized. The rest of the function
sequence of the device 100 according to the invention will be
explained step by step with reference to FIGS. 3 to 5.
[0017] FIG. 3 shows an end view of the device 100 according to the
invention in a position in which the clamping jaws 20, 20' are
engaged as much as possible into the device 2, especially far
enough so that the clamping jaws 20, 20' can grasp the stack of
sheet-shaped materials 1 over its entire length. In this position,
first clamping jaw 20 is located in the same plane as the tong
element 10, namely in contact with the outside of the stack of
sheet-shaped materials 1. As can be seen in FIG. 3, the center line
M of device 100 is offset somewhat to the right of the center of
the stack of sheet-shaped materials MB. By continuation of the
bracket guide 44' in combination with maximizing the distance
between the clamping jaws 20, 20', as described above, the clamping
jaws are aligned so that the center line MS of the carriage 30 lies
on the right relative to the center line M of the device 100 and
the center line MB of the stack of sheet-shaped materials 1.
[0018] The first and second tong bodies 24, 24' are each connected
by way of a first lever 26, 26', as well as a second lever 28, 28',
to the carriage 30. A drive that is not shown is mounted on the
carriage 30 between these levers 26, 26', 28, 28'. This drive
simultaneously moves a first linkage rod 31, which is connected at
a first linking point 29 with the first lever 26 of the left
clamping jaw, and a second linkage rod 31', which is connected at a
second linking point 29' with the first lever 26' of the second
clamping jaw 20'. In particular the linkage rods 31, 31',
constitute a mutual double-threaded rod.
[0019] If the drive, which is not shown, now moves the linkage rods
31, 31', the linking points 29, 29' move toward each other or away
from each other according to the direction of rotation of linkage
rods 31, 31'. Both linking points 29, 29' move, in this case, by
the same amount toward the center line MS of the carriage 30 or
away from it. Because of this, the positions of the first clamping
jaw 20 and the second clamping jaw 20' also continuously remain
symmetrical to the center line MS of the carriage 30. If the drive,
which is not shown, is now used to close the clamping jaws in this
position of the carriage, the carriage 30 must necessarily move
toward the left since the first clamping jaw 20 is already
contacting the stack of sheet-shaped materials 1. Since the
clamping jaws 20, 20' are continuously moved symmetrically to the
center line MS of the carriage 30, as described, at the moment when
the second clamping jaw 20' comes into contact with the stack 1,
the center line of the carriage MS necessarily coincides with the
center line MB of the stack 1 (see FIG. 4). In addition, the
clamping jaws 20, 20' have insertion aids 21, 21' in the front area
turned toward the device 2.
[0020] At a signal from the device 100, the device that has made
the stack of sheet-shaped materials 1 available releases the stack
of sheet-shaped materials 1 as soon as the clamping jaws 20, 20'
have securely gripped the stack of sheet-shaped materials 1. After
that, the carriage 30 moves, together with the clamping arrangement
and the stack 1, back into the initial position of the device 100.
During the return travel, the guide mandrel 33 visible in FIG. 2 in
turn engages in the bracket guide of the carriage 44, 44' so that
the carriage 30, together with its freight, is moved laterally,
during the movement in transport direction, far enough so that the
center line M of the device 100 coincides with the center lines MB
of the stack of sheet-shaped materials 1 and the center line MS of
the carriage 30 that already coincide with each other (see FIG. 5).
In this position, the stack of sheet-shaped materials is already
centered over the tray 50 of the vibrating table. At this point,
the stack of sheet-shaped materials 1 can be taken over by another
device, which is not shown for transporting the sheet-shaped
materials.
[0021] One of the linkage rods 31, 31' has a shaft encoder, which
is not shown, that sends the rotary movement of the linkage rods
31, 31' to a higher-level control, which is not shown. From the
signals from the shaft encoder, this control determines the
distance between the clamping jaws 20, 20'. When the tongs are
closed, this distance corresponds exactly to the stack thickness D
of the stack of sheet-shaped materials 1. In a first operating
mode, in which as just described a stack of sheet-shaped print
materials 1 is transported from the device 2, it is provided that a
holding force of the clamping jaws 20, 20' of at least 160 N will
be generated in order to ensure that there is no slipping of the
individual sheet-shaped materials in the stack 1. In a second
operating mode of the device 100, in which a stack of sheet-shaped
materials 1 is not to be taken over by the device 2, rather a stack
of sheet-shaped materials 1 is manually placed in order to make
this stack 1 available to devices that follow on the transport path
of the device 100, the device 100 is only used to determine the
stack thickness of the manually placed stack 1. In this operating
mode, the clamping jaws 20, 20' remain in a slightly open position
laterally above the tray 50 and at first are used to prevent
disarrangement of the sheets by the user that places the stack of
sheet-shaped materials 1 in the device 100 manually. The
sheet-shaped materials that are manually placed in the device 100
in this way are straightened at the tray 50 of the vibrating table.
Then the clamping jaws 20, 20' move together with a maximum holding
force of 40 N to determine the stack thickness D of the manually
placed stack of sheet-shaped materials 1 in order to make the
information regarding the stack thickness D available to the device
that follows the device 100. The determination of the stack
thickness D is carried out in this second operating mode the same
as in the first operating mode, only with reduced holding force
since, on one hand, an elevated holding force is not necessary
since the stack of sheet-shaped materials 1 does not have to be
transported and, on the other, in order to prevent injury to a user
during the measurement of the stack thickness D. As an additional
safety measure, a photoelectric barrier is provided that monitors
the upper area above the stack of sheet-shaped materials.
[0022] The second clamping jaw 20' is rocker-mounted at 19, with a
spring (not shown) for compensating variations in the thickness of
stack thickness D. The rocker is pressed outward upon contact with
the stack of sheet-shaped materials 1 and the further closing of
the clamping jaws 20, 20', whereby the springs of the rocker
mounting are pre-stressed. In addition, an optical switch, which is
not shown, is provided that monitors the position of the rocker.
Advantageously, the optical switch is designed in such a way, and
coordinated with the rocker springs in such a way, that the
movement of the clamping jaws 20, 20' is switched off together with
the rocker when a specified holding force is reached. This holding
force corresponds either to the 160 N that is required for the
transport of the stack of sheet-shaped materials or the 40 N for
thickness measurement without transport of the stack of
sheet-shaped materials 1.
[0023] At the same time, a signal from this optical switch that
corresponds to the closed status of the tongs can be used in order
to signal the collecting device that the device 100 is now securely
holding the stack of sheet-shaped materials and the collecting
device can release the stack of sheet-shaped materials 1.
Alternatively, a "tongs closed" signal can be generated so that the
device that has made the stack of sheet-shaped print materials 1
available releases it when the sensor that monitors the movement of
the clamping jaws 20, 20' toward each other no longer supplies any
pulses. The clamping jaws 20, 20' are then necessarily closed.
[0024] The alignment of the clamping jaws 20, 20' and the stack of
sheet-shaped materials in the transport direction may carried out
independently of the stack thickness. Because of this, it is
possible to achieve the alignment of the stack of sheet-shaped
materials in an especially flexible way, especially for a change
between different print orders that create stacks of sheet-shaped
materials with different thicknesses. The maximum thickness of the
stack of sheet-shaped materials depends on the clamping force that
the device according to the invention can make available for
clamping the stack of sheet-shaped materials. In addition, the
maximum thickness of the stack depends on the movement capability
of the clamping jaws, especially on the distance that these
clamping jaws can move with respect to each other. The thickness of
the stack is also limited by the subsequent processing steps. If
the sheet-shaped materials are bound after transport, e.g. by means
of wire comb binding, stapling, adhesive binding, spiral binding or
other binding processes, the available binding element also
restricts the thickness of the stack.
[0025] The sheet-shaped materials may be clamped so that they are
vertical between the clamping jaws. On one hand, this results in
special demands on the available holding force of the clamping jaws
since the sheet-shaped materials in the stack must be pressed
together in such a way that they are not displaced with respect to
each other because of their inherent weight; on the other hand, the
vertical position of the sheet-shaped materials in the stack, which
generally consist of flexible material, e.g. paper, prevents the
stack from deforming, i.e. from deviating from a shape that is
essentially square.
[0026] The clamping jaws may be linked with the carriage and to
each other by way of a parallelogram. Advantageously, the carriage
thereby remains continuously centered between the clamping jaws. In
this way, a superimposing of the center lines of the stack of
sheet-shaped materials and the center line of the carriage can be
achieved in a simple way.
[0027] The device 100 may be open on both sides of the stack of
sheet-shaped materials. This means the clamping jaws only grip the
stack on the side and permit running in laterally, around a stack
of sheet-shaped materials, e.g. in order to take the stack out of
the device 2, and, on the other hand, in order to move the clamping
jaws laterally away from the stack so that after transport and
delivery of the stack to the next device in sequence, the clamping
jaws can move back to their starting position. In this way, the
necessity of the clamping jaws carrying out a vertical movement is
dispensed with.
[0028] At least one of the clamping jaws may be mounted in such a
way that the clamping jaws adapt to stacks of sheet-shaped
materials that are not uniform in thickness. This is especially
important if the stack consists of printed sheet-shaped materials.
Because of uneven toner application, in some cases there can be
considerable variations in the thickness of a stack over its area.
By using a rocker-like mounting for at least one of the clamping
jaws, it is possible to compensate such variations in thickness and
attain a holding force that is distributed uniformly along the
clamping jaw surfaces.
[0029] The device may have measuring devices, by means of which the
thickness of the stack of sheet-shaped materials is determined.
Advantageously, measurement of the stack thickness can be carried
out even without transporting the stack of sheet-shaped materials.
In one embodiment, the measuring device is a sensor disk that is
coupled to the movement of the clamping jaws. Advantageously,
measurement of the stack thickness is carried out at first with a
maximum pressure of 40 N.
[0030] The device may have a protective device that can switch off
the clamping movement. In particular, the protective device
contains a photoelectric barrier that monitors the space above the
stack of sheet-shaped materials that is clamped in the clamping
jaws.
[0031] The device may take the stack of sheet-shaped materials out
of a collecting device for sheet-shaped materials.
[0032] Although the invention has been described and illustrated
with reference to specific illustrative embodiments thereof, it is
not intended that the invention be limited to those illustrative
embodiments. Those skilled in the art will recognize that
variations and modifications can be made without departing from the
true scope and spirit of the invention as defined by the claims
that follow. It is therefore intended to include within the
invention all such variations and modifications as fall within the
scope of the appended claims and equivalents thereof.
* * * * *