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Claims  |
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What is claimed is:
1. A rotary printing press comprising:
a plurality of blanket cylinders forming a plurality of print positions,
each of said plurality of blanket cylinders forming one of said plurality
of print positions with another of said blanket cylinders;
a plurality of plate cylinders, each of said plate cylinders being combined
with one of said plurality of blanket cylinders to form a plurality of
cylinder pairs;
a plurality of drives, each of said plurality of drives separately driving
one of said plurality of cylinder pairs, said each drive including a motor
and a toothed belt driving a respective said blanket cylinder from said
motor, said each drive also including a mechanical coupling drivingly
connecting a respective said blanket cylinder to a respective said plate
cylinder, each said plate cylinder being driven through a respective said
mechanical coupling from power taken off from a respective said blanket
cylinder.
2. The press in accordance with claim 1, further comprising:
an inking system with an inking roller associated with each of said
cylinder pairs, said inking roller being one of mechanically coupled with
a respective said cylinder pair and a separate ink drive.
3. The press in accordance with claim 2, wherein:
said ink drive includes an ink motor and a toothed belt connecting said ink
motor to said inking roller.
4. The press in accordance with claim 1, further comprising:
control means for controlling one of a speed and a position of said
cylinders, said control means including a set value transducer for
providing a desired value of said one of speed and position for said
cylinders, said control means also including an actual value transducer
for measuring an actual value of said one of speed and position of said
cylinders, said control means also includes a regulator for adjusting
operation of said motor dependent on a difference between said desired
value and said measured actual value.
5. The press in accordance with claim 4, wherein:
said measured actual value sent by said actual value transducer forms a
principal control variable for said regulator.
6. The press in accordance with claim 4, wherein:
said control means operates without input from a mechanical actual value
transducer determining one of position and speed of rotation of said
motor.
7. The press in accordance with claim 4, further comprising:
a mechanical transmitter on one of said motors and generating an output
signal used for an emergency shut down of said one motor.
8. The press in accordance with claim 4, wherein:
one of said blanket cylinders of said cylinder pairs has a torque-free
shaft end not directly driven by said motor, said actual value transducer
is arranged on said torque-free shaft end.
9. The press in accordance with claim 1, wherein:
one of said cylinder pairs is on a first printing side, two of said
cylinder pairs are on a second printing side.
10. The press in accordance with claim 9, wherein:
a blanket cylinder of said one cylinder pair forms a counter pressure
cylinder for said two cylinder pairs, each one of said two cylinder pairs
being usable alternately.
11. The press in accordance with claim 1, wherein:
two of said cylinder pairs are arranged horizontally opposite each other
and are combined to form a cylinder unit, said two cylinder pairs are
mounted in a machine frame independently of a third of said cylinder
pairs.
12. The press in accordance with claim 11, wherein:
said cylinder unit is arranged in one of a Y-shape and an A-shape with said
third cylinder pair.
13. The press in accordance with claim 1, wherein:
said toothed belt forms a coupling between respective said blanket
cylinders and said motors which is substantially clearance free, elastic
and forms a high damping coupling between respective said blanket
cylinders and motors, said toothed belt of said respective drives forms a
low-pass filter between said respective motor and blanket cylinder, said
drive means each includes an infinitely variable transmission in
combination with respective said toothed belts.
14. The press in accordance with claim 1, wherein:
each said print position forms a passage for a web between two respective
said blanket cylinders forming said each print position, said two blanket
cylinders which form a respective said print position perform printing on
opposite sides of the web.
15. The press in accordance with claim 1, wherein:
said mechanical coupling forms a direct driving of a respective said
blanket cylinder by a respective said motor.
16. The press in accordance with claim 1, wherein:
one of said blanket cylinders forms more than one of said print positions
with other said blanket cylinders.
17. The press in accordance with claim 14, wherein:
one of said blanket cylinders forms more than one of said print positions
with other said blanket cylinders.
18. The press in accordance with claim 14, wherein:
one of said print positions is formed by a first set of said plurality of
blanket cylinders and another of said print positions are formed by a
second set of said plurality of blanket cylinders, said first and second
set of blanket rollers being mutually exclusive.
19. The press in accordance with claim 1, further comprising:
a control device for adjusting a circumferential register of one said
blanket cylinders with another of said blanket cylinders.
20. Rotary printing machine comprising:
a blanket cylinder;
a plate cylinder;
mechanical coupling means for mechanically coupling together said plate
cylinder and said blanket cylinder in a manner to be commonly driven, said
mechanical coupling means and said blanket and plate cylinders having a
load mass moment of inertia;
drive means including a drive motor with a toothed belt for directly
driving one end of one of said blanket cylinder and said plate cylinder,
the other of said blanket and plate cylinder being correspondingly driven
by said mechanical coupling means, said drive means having a drive mass
moment of inertia, said load mass moment of inertia being larger than said
drive moment mass of inertia, said toothed belt forming a low pass filter
between said drive mass moment of inertia and said load mass moment of
inertia;
control means for controlling one of a speed and a position of said
cylinders, said control means including set value transducer means for
providing a desired value of said one of speed and position for said
cylinders, said control means also including an actual value transducer
means for measuring an actual value of said one of speed and position of
said cylinders, said control means also includes a regulator for adjusting
operation of said motor dependent on a difference between said desired
value and said measured actual value, said actual value transducer being
arranged on another end of said one of said blanket and plate cylinder.
21. The press in accordance with claim 20, wherein:
said control means adjusts a circumferential register of one said blanket
cylinders with another of said blanket cylinders.
22. Rotary printing machine comprising:
a first blanket cylinder;
a first plate cylinder;
first mechanical coupling means for mechanically coupling together said
first plate cylinder and said first blanket cylinder in a manner to be
commonly driven;
first blanket drive means including a drive motor and a toothed belt for
directly driving said first blanket cylinder, said first plate cylinder
being correspondingly driven by said first mechanical coupling means;
a second blanket cylinder;
a second plate cylinder;
second mechanical coupling means for mechanically coupling together said
second plate cylinder and said second blanket cylinder in a manner to be
commonly driven;
second blanket drive means including a drive motor and a toothed belt for
directly driving said second blanket cylinder, said second plate cylinder
being correspondingly driven by said second mechanical coupling means,
said second drive means separately driving said second blanket cylinder
from driving of said first blanket cylinder;
a counterpressure cylinder positioned adjacent said first and second
blanket cylinders, said blanket cylinders and said counterpressure
cylinder forming first and second print positions between themselves for
passing a web between said counterpressure cylinder and said first and
second blanket cylinders at said first and second print positions, said
counterpressure cylinder being mechanically drivably isolated from said
first and second drive means;
counter pressure drive means including a motor for separately driving said
counterpressure cylinder from driving of said first and second blanket
cylinders. |
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Claims |
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Description |
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FIELD OF THE INVENTION
The present invention pertains to the integration of cylinders of a rotary
printing machine into individual cylinder groups.
BACKGROUND OF THE INVENTION
Prior-art rotary printing machines are driven by a main drive via a
mechanical longitudinal shaft, also called a vertical shaft. One
disadvantage of these printing machines is the mechanical effort that
needs to be taken to compensate the torsion of the longitudinal shaft
occurring during operation. As a result, it is necessary to mechanically
adjust the circumferential register of print positions of the printing
machine during operation.
Attempts have also been made to replace the mechanical longitudinal shaft
between the individual printing units with an electrical longitudinal
shaft. Thus, each printing unit receives a separate electrical drive. In
addition to the high mechanical expense that continues to be necessary
because of the complex nature of the individual printing units with a
plurality of print positions, there is in this case a high expense for
control technique, because synchronous operation of the individually
driven printing units with one another must be guaranteed as well.
To avoid the above-mentioned problems, DE 41,38,479 A1 proposes that the
cylinders of the printing machine be driven by one electric motor each.
DE 42,14,394 A1 discloses a process control system for such a printing
machine with individually driven cylinders. The individual drives of the
cylinders and their drive regulators can be arbitrarily integrated into
print position groups. The print position groups are associated with
folders, from which they obtain their position reference. The process
control system proposed consists essentially of a high-speed BUS system
for the individual drives and the drive regulators of a print position
group and of a higher process control system for managing the print
position groups.
Even though the design of the individually driven cylinders pursued in
these two documents ensures a high level of flexibility in use, it also
requires a very great number of drive motors at the same time, and, as is
shown by DE 42,14,394 A1, a very high expense for regulating this great
number of individual drives. Moreover, a great variety of motors must be
used. If only a few motor sizes were used, it would otherwise frequently
be necessary to use oversized motors for different applications. Both
drive up the price of such a printing machine.
SUMMARY AND OBJECTS OF THE INVENTION
In contrast to the state of the art, the object of the present invention is
to provide a rotary printing machine that can be used in a highly flexible
manner and which is yet economical.
According to the present invention, blanket cylinders and plate cylinders
of a rotary printing machine form in pairs a cylinder group, in which one
blanket cylinder and one plate cylinder are mechanically coupled with one
another and are driven together by a separate drive motor per cylinder
group.
The number of the necessary drive motors is considerably reduced due to
this group integration of the two cylinders and due to their being
provided with a single drive for at least one cylinder pair; the number of
the necessary drive motors is reduced by at least half compared with the
individual drive designs. The mechanical coupling of these two cylinders,
which are associated with one another in terms of printing technique,
which is preferably a gear coupling with spur-toothed or helical gears,
offers considerable advantages in terms of price over the design of the
individually driven cylinders. No substantial concessions are to be made
in terms of the flexibility of use compared with the individual drive
design. Thus, both the circumferential register adjustment and the lateral
register adjustment of each blanket cylinder can be performed individually
and, if necessary, coordinated with each additional blanket cylinder.
Technically and economically optimal print positions can be formed in a
rotary printing machine due to the cylinder groups according to the
present invention with separate drive motors. The print positions are
defined in this connection as the cylinder pairs between which a web of
paper to be printed on passes through and is printed on one side or on
both sides. Consequently, one cylinder group and a corresponding
counterpressure cylinder, which may, but does not have to, belong to the
cylinder group, belong to a print position formed according to the present
invention. However, the print positions of the printing machine are
mechanically independent in terms of the drive technique in both cases,
i.e., the print positions of the printing machine are electrically coupled
with one another.
The blanket cylinder is preferably driven in the cylinder groups according
to the present invention, and the blanket cylinder in turn drives the
plate cylinder of the same cylinder group via the mechanical coupling.
However, it is also possible to drive the plate cylinder shaft in another
embodiment of the present invention, so that the blanket cylinder is
driven only via the mechanical drive from the plate cylinder. While the
drive of the plate cylinder advantageously requires a small effort for
engaging and disengaging the blanket cylinder, the blanket cylinder is, on
the other hand, decisive for the positional accuracy and the
circumferential register adjustment. The first solution offers the
advantage that the cylinder, which ultimately comes directly into contact
with a web of paper to be printed on, does not need to be driven via a
transmission member that may possibly have a clearance.
It is advantageous to always allow three cylinder groups to work on one
print position. One cylinder group is arranged on one printed side, and
two cylinder groups are arranged on the opposite printed side of a web of
paper passing through between them. The blanket cylinder of the cylinder
group arranged on one printed side of the web of paper preferably forms
the counterpressure cylinder for the other two blanket cylinders of the
cylinder groups arranged on the opposite printed side of the web of paper,
and the latter cylinder groups are advantageously both driven
alternatingly. This configuration offers the highest flexibility of use
for a blanket/blanket production, because the two blanket cylinders that
can be used alternatingly during ongoing production can be configured for
changing over the print. This is performed by changing the plate of a
plate cylinder associated with the non-engaged blanket cylinder. Each
cylinder group can be mounted in an individual stand. The two cylinder
groups located horizontally opposite one printed side of the web of paper
are preferably integrated into a cylinder unit mounted in a stand.
According to the present invention, a cylinder group can be expanded by one
counterpressure cylinder for the blanket cylinder. This third cylinder of
the cylinder group thus formed is mechanically coupled with the blanket
cylinder, preferably by an additional gear coupling. Such a cylinder group
already represents a print position, between the blanket cylinder and
counterpressure cylinder of which the web of paper to be printed on is
passed through. The counterpressure cylinder may be a steel cylinder or
another blanket cylinder for two-sided printing. Such a counterpressure
cylinder may also especially be a central cylinder of a cylinder unit
with, e.g., nine or ten cylinders. In an alternative, equally preferred
embodiment of the present invention, such a central cylinder is driven by
a separate drive motor. This type of integration guarantees the highest
flexibility of use for a cylinder unit. Thus, each of the cylinder groups
associated with the central cylinder can be reversed in this case
individually and independently from the other cylinder groups, which is
necessary, e.g., for alternate printing or for flying plate change.
The individual cylinder group is driven from a drive motor by means of a
toothed belt. Such a toothed belt has a high elasticity compared with the
solution proposed in DE 41,38,479 A1, according to which the rotor of the
electric motor is mounted on the drive shaft of the driven cylinder.
However, as will be explained later, the high damping of the mechanical
system consisting of a drive motor and the driven cylinders is of great
value for the control design of the drive of a cylinder group. However,
the present invention also permits, in principle, direct drive, which may
even be advantageous in the case of small cylinders. Compared with a gear
drive between the drive motor and the driven cylinder of a cylinder group,
which may also be used, a toothed belt offers the advantage of a
clearance-free operation and of a not absolutely fixed transmission ratio.
In contrast, gears are provided for the mechanical coupling between the
cylinders within one cylinder group, even though other transmission
members are also conceivable. The mutually meshing gears may be spur gears
or helical gears. In the case of spur gears, the blanket cylinder is
longitudinally displaced for lateral register adjustment, while its
driving and/or driven gears remain stationary according to the present
invention. Otherwise, a circumferential register adjustment would also be
necessary along with the lateral register adjustment. When spur gears are
used, the blanket cylinder is simply displaced longitudinally together
with its stationarily arranged gear or gears.
The inking roller or inking rollers of an inking system, which is/are
associated with one cylinder group, can be mechanically coupled with that
cylinder group according to the present invention, so that the inking
roller or inking rollers is/are also driven from the drive motor of that
cylinder group. The expense in terms of control (also referred to herein
as control technique) can be kept low due to this solution. On the other
hand, the mechanical coupling of the inking system according to the
modular system pursued by the present invention is not quite so ideal as
the more highly preferred individual drive for the roller or rollers of
the inking system. Thus, each inking system has a separate drive motor for
its inking rollers. Such a drive motor also preferably drives the inking
roller or, in the case of a plurality of inking rollers, the inking roller
located closest to the plate cylinder of the corresponding cylinder group
via a clearance-free toothed belt with high damping and, if desired, via a
reduction gear. The circumferential velocity of this inking roller is
advantageously adjustable, especially with a negative slip in relation to
the plate cylinder, so that the circumferential velocity of the inking
roller is somewhat lower than that of the corresponding plate cylinder.
The positions of at least the drive motors of the cylinder groups of one
cylinder unit operating on the same printed side of a web of paper are
advantageously controlled. A so-called ideal position control, i.e., a
delay-free position control with contouring error correction is preferred.
However, this expensive type of position control, which is desirable for
technical reasons, can be definitely dispensed with. A simple position
control also represents a preferred, especially inexpensive embodiment of
the present invention.
The position and/or the speed of rotation of the cylinder of a cylinder
group or of a roller of an inking system to be controlled are controlled
according to the present invention by means of a regulator for the drive
motor by the variance comparison of the output signals of a set value
transducer and of an actual value transducer, wherein the actual value
transducer determines the position and/or the speed of rotation of the
cylinder or roller. In contrast to the prior-art controls in rotary
printing machines, a load transducer is thus used for control. In
contrast, a mechanical transducer on the motor side has hitherto been used
in the construction of printing machines to determine the motor speed or
the angular position of the rotor of the motor for the variance comparison
of the motor control. The dynamic limits are rapidly reached with this
prior-art control in the case of high mass inertia ratios of the load to
the motor. If the control becomes unstable, especially the motor begins to
vibrate, while the load remains relatively still.
Difference correction means, control cascades, and active filters are used
in control technique for so-called two-mass oscillators, but they require
a high expense for control technique. It was surprisingly found to be
fully sufficient for the above-described load/motor systems, i.e., the
individually driven cylinder groups, to lead the control essentially by
means of an actual value, which was determined by an actual value
transducer arranged on the load, namely, on one of the cylinders of a
cylinder group. This actual value-distance-angular position and/or speed
of rotation of the corresponding cylinder is already sufficient alone to
achieve high dynamics and control performance.
By obtaining the actual value to be controlled according to the present
invention from the load, what must operate accurately, namely, the load,
rather than the motor, is measured. The mechanical equivalent system
consisting of the drive motor, a coupling and the load can be considered
to be a low-pass filter. The low-pass filter of the
motor-coupling-load-distance system is used in this type of control to
filter impacts and vibrations, which are generated in the control system.
Such impacts and vibrations are thus fed back into the regulator to a
reduced extent. The risk of a build-up is reduced as a result. The
dynamics of the control and consequently also the control performance can
be substantially increased as a result compared with the prior-art control
described, with identical coupling.
The actual value transducer, which has migrated, symbolically speaking,
from the motor side to the load side, forms the principal controlled
variable for the regulator of the motor, i.e., the motor is led from the
load side by its actual value. According to an especially preferred
embodiment of the present invention, no mechanical actual value transducer
is needed for determining the position or the speed of rotation of the
motor within the framework of the control of the motor. An actual value
determination that may optionally be integrated within the motor can
advantageously be used for exclusive drive monitoring, if desired, for
switching off the motor.
The actual value transducer for the control is arranged, according to the
present invention, at the torque-free shaft end of the driven cylinder of
a cylinder group or of the driven roller of an inking system.
Asynchronous electric motors are used especially advantageously as the
drive motors. An asynchronous motor has hitherto been used only when a
small load was to be driven by means of a large motor. The use of
asynchronous motors has been known for this case, in which a drive motor
drives a cylinder group or even the rollers of an inking system, in which
the mass inertia ratio of the load driven to the drive motor is relatively
high. Asynchronous motors are particularly suitable for the purpose of
control according to the present invention with a load transducer instead
of a motor transducer. Asynchronous motors have a higher field rigidity
than the d.c. motors used to date for these applications, so that their
use improves the dynamics and the control performance of the system to be
controlled. However, the use of other types of motors, e.g., d.c. motors,
is not excluded, in principle.
The stability of the control is additionally improved by the preferred use
of a clearance-free toothed belt with high damping as a coupling means
between the motor and the load.
The drive motor may even be left out of consideration in the two-mass
oscillator in question. The load, acting as a low-pass filter, is
insensitive to the vibrations of the motor, which is much smaller compared
with it. On the other hand, the reactions from the load to the drive motor
can be ignored.
A maximum of flexibility is achieved with the design of integrating blanket
cylinders and plate cylinders in pairs into cylinder groups, and, if
desired, along with another counterpressure cylinder, while the price of a
printing machine thus organized can be considerably reduced compared with
a printing machine with individually driven cylinders. Drive motors of
only two or at most three output classes are needed for a printing machine
composed of such cylinder groups, while separate motors for cylinders with
a great variety of different lengths and diameters are basically required
in the case of directly and individually driven cylinders. The mass
inertia ratios of the load to the motor, which may possibly vary within a
wide range, can be absorbed and adjusted to one another by means of the
toothed belt drive used according to the present invention. The reduction
in the number of drive motors, together with the advantage that motors of
only a few output classes must be provided, already offers considerable
advantages in terms of price. This advantage is further enhanced by the
use of the simple control according to the present invention, which is
also flexibly adaptable to varying mass inertia ratios. The advantages
achieved with the present invention become increasingly significant with
increasing size of the printing machines, i.e., with increasing number of
printing units and print positions per machine. The present invention is
used especially in the construction of rotary offset printing machines,
but it is not limited to them.
Preferred exemplary embodiments of the present invention will be explained
below on the basis of the figures. Additional features and advantages of
the present will be disclosed.
The various features of novelty which characterize the invention are
pointed out with particularity in the claims annexed to and forming a part
of this disclosure. For a better understanding of the invention, its
operating advantages and specific objects attained by its uses, reference
is made to the accompanying drawings and descriptive matter in which
preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic view showing a print position with two cylinder
groups according to the invention;
FIGS. 2A and 2B are a schematic views showing a print position with one
cylinder group according to the invention;
FIG. 3 is a schematic view showing a cylinder unit with an individually
driven central cylinder and four cylinder groups according to the
invention;
FIG. 4 is a top view of a cylinder group with an associated, individually
driven inking roller according to the invention;
FIG. 5 is a diagram showing the control of the drive for a cylinder group
corresponding to the state of the art;
FIG. 6 is a diagram showing the control for the drive of a cylinder group
according to the present invention;
FIG. 7 is a graph showing a comparison of the dynamic behavior of a
prior-art control and of a control according to the present invention as a
function of the mass inertia ratio of the motor to the load;
FIG. 8 is a graph showing a comparison of the dynamic behavior of a
prior-art control and of a control according to the present invention as a
function of the torsional rigidity of the coupling between the motor and
the load,
FIG. 9 is a control diagram of the regulator, according to the invention;
FIG. 10 is a schematic view showing a print position formed by three
cylinder groups in the Y position; and
FIG. 11 a schematic view showing a print position formed by three cylinder
groups in the lambda position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a print position shown in FIG. 1, a web of paper 1 to be printed on is
passed through between the two blanket cylinders 2 of two cylinder groups
10 located opposite each other. The two cylinder groups 10 are formed by
the blanket cylinder 2 and an associated plate cylinder 3 each, which are
mechanically coupled to one another for the common drive. The mechanical
coupling is schematically indicated by a connection line between the
centers of the two cylinders 2 and 3. In the exemplary embodiment
according to FIG. 1, the blanket cylinders 2 of each cylinder group 10 are
driven by a three-phase motor 5. The configuration corresponding to FIG.
1, in which only one blanket cylinder 2 and one plate cylinder 3 are
integrated into a cylinder group 10 by a mechanical coupling, is
characterized by its simple design and the highest possible degree of
configuration freedom in forming print positions and groups of print
positions.
FIGS. 2A, 2B show a variant for forming a print position, in which a
counterpressure cylinder 4 for the blanket cylinder 2 is mechanically
coupled with that blanket cylinder 2. In this exemplary embodiment, the
cylinder group 10 consists of the blanket cylinder 2, its counterpressure
cylinder 4 and the plate cylinder 3 and its mechanical coupling, so that
the print position is formed by a single cylinder group 10. In contrast to
FIG. 1, the plate cylinder 3 associated with the blanket cylinder 2,
rather than the blanket cylinder 2 is driven by a three-phase motor 5 in
the exemplary embodiment according to FIGS. 2A, 2B. The advantage of this
variant for integrating cylinders into a cylinder group is its constant
delivery behavior because of the mechanical coupling of the blanket
cylinder 2 with its counterpressure cylinder 4, and that the cylinders 2
and 4 do not mutually directly affect each other because of this
mechanical coupling. The counterpressure cylinder 4 may be a second
blanket cylinder or a steel cylinder, e.g., a central cylinder of a
9-cylinder or 10-cylinder unit.
The association of the motors 5 with the blanket cylinders 2 or the plate
cylinders 3 can be reversed, in principle, in both exemplary embodiments.
Driving the plate cylinder 3 offers the advantage that the cylinder group
10 can be reversed more easily, while in the other case, in which the
blanket cylinder 2 is driven, the cylinder directly printing on the web of
paper 1 is driven, and driving free from transmission members, e.g.,
gears, which may have a clearance, is possible as a result.
FIG. 3 shows a cylinder unit 20 comprised of a central steel cylinder 6 and
four cylinder groups 10 associated with that central cylinder 6. One
blanket cylinder 2 and one plate cylinder 3 each are integrated into one
cylinder group 10 in this exemplary embodiment. A separate three-phase
motor 5 is provided for driving the central cylinder 6. However, the
central cylinder 6 could also form a cylinder group corresponding to the
variant shown in FIG. 2 with one of the four cylinder groups 10. The
separate motor 5 for the central cylinder 6 would be eliminated as a
result. However, on the other hand, the integration (shown in FIG. 3) into
the smallest possible cylinder groups 10 and the individually driven
central cylinder 6 into a cylinder unit 20 offers the highest possible
flexibility in terms of the possibilities of configuration. This
configuration of a cylinder unit 20, derived from the above-described
basic variants, offers the printing technical advantage that the so-called
fan-out effect remains within very narrow limits. Furthermore, each of the
blanket cylinders 2 can be reversed to blanket/blanket production in a
simple manner. The possibilities of reversing to various types of
alternate printing are not limited, either.
As this exemplary embodiment shows, a cylinder group 10 formed from
cylinder pairs is equival | | |
