U.S. patent number RE34,970 [Application Number 07/862,704] was granted by the patent office on 1995-06-20 for method and apparatus for printing with a lithographic sleeve.
This patent grant is currently assigned to Tittgemeyer Engineering GmbH. Invention is credited to Udo Tittgemeyer.
United States Patent |
RE34,970 |
Tittgemeyer |
June 20, 1995 |
Method and apparatus for printing with a lithographic sleeve
Abstract
A printing method and apparatus which use a sleeve-shaped
printing form attached to a rotating body. The sleeve-shaped form
conveniently permits the printing operation to be performed
continuously and on both sides of the print career simultaneously.
The sleeves preferably exhibit a number of process-specific
functional layers. Exemplary layers are: (1) a supporting metal
sleeve, (2) an intermediate metal layer for carrying the ink, and
(3) a surface metal layer for carrying the water. Copper is an
exemplary intermediate layer, and chromium is used as the surface
metal layer.
Inventors: |
Tittgemeyer; Udo (Arnsberg,
DE) |
Assignee: |
Tittgemeyer Engineering GmbH
(DE)
|
Family
ID: |
6288148 |
Appl.
No.: |
07/862,704 |
Filed: |
April 3, 1992 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
940438 |
Dec 11, 1986 |
|
|
|
Reissue of: |
293589 |
Jan 3, 1989 |
04913048 |
Apr 3, 1990 |
|
|
Foreign Application Priority Data
|
|
|
|
|
Dec 11, 1985 [DE] |
|
|
35 43 704.9 |
|
Current U.S.
Class: |
101/141; 101/216;
101/375; 101/451 |
Current CPC
Class: |
B41F
13/20 (20130101); B41C 1/1075 (20130101); B41F
27/105 (20130101); B41P 2227/21 (20130101); B41P
2217/15 (20130101); B41P 2213/804 (20130101) |
Current International
Class: |
B41C
1/10 (20060101); B41F 27/10 (20060101); B41F
27/00 (20060101); B41F 007/20 () |
Field of
Search: |
;101/217,218,216,220,137,142,143,144,375,376,219,141 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0076777 |
|
Apr 1983 |
|
EP |
|
228483 |
|
Apr 1909 |
|
DE |
|
282136 |
|
Feb 1915 |
|
DE |
|
470994 |
|
May 1927 |
|
DE |
|
490994 |
|
Aug 1927 |
|
DE |
|
493693 |
|
May 1928 |
|
DE |
|
470937 |
|
Feb 1929 |
|
DE |
|
897107 |
|
Apr 1942 |
|
DE |
|
39744 |
|
Oct 1969 |
|
DE |
|
2700118 |
|
Jul 1977 |
|
DE |
|
2708689 |
|
Sep 1977 |
|
DE |
|
107841 |
|
Jul 1982 |
|
JP |
|
300964 |
|
Nov 1954 |
|
CH |
|
345023 |
|
Apr 1960 |
|
CH |
|
646377 |
|
Nov 1984 |
|
CH |
|
710906 |
|
Jun 1954 |
|
GB |
|
763639 |
|
Dec 1956 |
|
GB |
|
2015929 |
|
Sep 1979 |
|
GB |
|
Primary Examiner: Bennett; Chris A.
Attorney, Agent or Firm: Koch; Robert J. Davis; Peter J.
Parent Case Text
This application is a continuation of application Ser. No. 940,438
filed Dec. 11. 1986, now abandoned.
Claims
I claim:
1. A method for offset printing comprising:
releasably mounting a sleeve-shaped print form to a cylindrical
routing body, said sleeve-shaped print form comprising a first
material layer for absorbing water and a second material layer for
absorbing ink, by frictionally fitting and radially supporting an
inner surface of said sleeve-shaped print form to an outer surface
of said rotating body along a longitudinal extent of said print
form;
contacting said sleeve-shaped print form with an ink; printing a
carrier material with ink from said second material layer;
completing the printing of said carrier material;
unilaterally releasing a single end of said rotating body from a
frame-mounted bearing;
removing said print form from said rotating body by axially pulling
said print form past said end of said rotating body connected to a
releasable bearing;
replacing said print form with a second sleeve-shaped print form by
axially inserting said second print form over said end of said
rotating body;
engaging said rotating body through said releasable bearing with
said frame; and
printing a carrier material.
2. A method according to claim 1, wherein the step of releasably
mounting said sleeve-shaped form frictionally holds said form to
said rotating body.
3. A method according to claim 1, wherein the fitting step
comprises;
expanding an inner surface of said print form by exposing said
inner surface to pressure of a medium
pushing the expanded sleeve-shaped form over said rotating body;
and
releasing said pressure.
4. A method according to claim 1, wherein releasing comprises
pivoting a rotating body mounting bearing away from said rotating
body.
5. A method according to claim 1, wherein releasing comprises
retracting a bearing mount axially from an end of said rotating
body and pivoting said rotating body at a second end.
6. A method according to claim 1, wherein releasing comprises
removing said rotating body from said frame.
7. An offset printing apparatus comprising:
a cylindrical rotating body bearingly supported in a frame;
a releasable bearing connected to said frame and supporting an end
of said cylindrical rotating body;
a sleeve-shaped print form comprising a first water absorbing layer
and a second ink retaining layer defining an ink transferring
pattern deposited on an outer surface and a third support layer
defining an inner support layer supporting said first and second
layers, said sleeve-shaped form is mounted and radially supported
on said cylindrical rotating body;
wherein said sleeve-shaped print form exhibits a low wall thickness
relative to a diameter of said print form;
an ink transfer cylinder rotatingly mounted in said frame adjacent
to said sleeve-shaped print form; and
an inking unit and a wetting unit mounted on said frame, adjacent
to said sleeve-shaped print form;
wherein said apparatus is configured to allow axial removal of said
print form from said cylindrical rotating body without removal of
said rotating body from said frame.
8. An apparatus according to claim 7, wherein said sleeve-shaped
print form is configured as a plate cylinder.
9. An apparatus according to claim 7, wherein said sleeve-shaped
print form is an image carrier and mounted on an offset
cylinder.
10. An apparatus according to claim 7 wherein said third layer is
about 0.3 mm thick.
11. An apparatus according to claim 7 wherein said first and/or
second layers have been deposited on said third layer.
12. An apparatus according to claim 7, wherein said material
defining said ink transferring pattern is metal.
13. An apparatus according to claim 7, wherein said material
defining said ink transferring pattern is a plastic.
14. An apparatus according to claim 13, wherein said plastic is
light sensitive.
15. An apparatus according to claim 7, further comprising an air
cushion between said rotating body and said print form actuable for
lifting said sleeve shaped print form for mounting.
16. An apparatus according to claim 7, further comprising a
pivoting mount connected to said first end of said rotating body
arranged in a recess in said frame exhibiting a clearance larger
than a cross section of said sleeve shaped print form.
17. An apparatus according to claim 16, further comprising a fixed
cantilever bearing support connected to a second end of said
rotating body.
18. An apparatus according to claim 7, further comprising:
a longitudinally displaceable pressure piece connected to a first
end of said rotating body; and
a pivoting journal connected to a second end of said rotating
body.
19. An apparatus according to claim 7, wherein said sleeve shaped
print form comprises:
an inner support cylinder and a seamless elastic outer coating
surrounding said inner support cylinder.
20. An apparatus according to claim 7, wherein said ink transfer
cylinder comprises a seamless elastic coating surrounding a
removable sleeve.
21. An offset printing apparatus comprising:
a frame;
a first stationary bearing connected to said frame;
a second releasable beating connected to said frame and releasably
connected to said cylindrical rotating body;
a sleeve-shaped print form comprising at least a first water
absorbing layer and a second ink retaining layer defining an ink
transferring pattern deposited on an outer surface and a third
support layer defining an inner support layer supporting said first
and second layers, said sleeve-shaped form is mounted and radially
supported on said cylindrical rotating body;
an ink transfer cylinder rotatingly mounted in said frame adjacent
to said sleeve-shaped print form; and
an inking unit and a wetting unit mounted on said frame, adjacent
to said sleeve-shaped print form;
wherein said first and second bearings, said frame and said
cylindrical rotating body are configured to allow axial
installation and removal of said print form over said cylindrical
rotating body with said cylindrical rotating body fixed to said
first bearing and released from said second bearing.
22. An apparatus according to claim 21, wherein said first
stationary beating is a pivot cantilever bearing means for
retaining said cylindrical rotating body in a pivoted position.
23. An apparatus according to claim 21, wherein said first
stationary bearing is a cantilever bearing and said second
releasable bearing is a pivot bearing configured to release said
cylindrical rotating body and pivot clear of a print form
installation path. .Iadd.
24. An offset printing apparatus comprising:
a frame;
a cylindrical rotating body supported in said frame;
a replaceable print form comprising at least a first water
absorbing layer and a second ink retaining layer defining an ink
transferring pattern deposited on an outer surface; said
replaceable print form is mounted and radially supported on said
cylindrical rotating body;
an ink transfer cylinder rotatingly mounted in said frame adjacent
to said replaceable print form;
a first stationary support connected to said frame;
a second releasable support connected to said frame and releasably
connected to said ink transfer cylinder;
a transfer sleeve mounted and radially supported on said ink
transfer cylinder; and
an inking unit and a wetting unit mounted on said frame, adjacent
to said replaceable print form;
wherein said first and second supports, said frame and said ink
transfer cylinder are configured to allow axial installation and
removal of said transfer sleeve over said ink transfer cylinder
with said ink transfer cylinder fixed to said first support and
released from said second support. .Iaddend. .Iadd.
25. An apparatus according to claim 24 wherein said replaceable
printing form is a sleeve-shaped print form. .Iaddend. .Iadd.
26. An apparatus according to claim 24 wherein said transfer sleeve
exhibits an outer rubber layer. .Iaddend. .Iadd.27. An apparatus
according to claim 24, further comprising an air cushion between
said transfer cylinder and said transfer sleeve actuable for
lifting said transfer sleeve for mounting. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process and apparatus for printing of
print carriers and, more particularly, a rotating body supported in
rotating fashion with a printing form, mounted on a body surface
facing a print carrier and supported on a stand. The invention
particularly relates to printing on print carriers in an offset
printing machine with one or more printing units, each comprising a
printing form and a transfer cylinder, together with a dampening
system and an inking system, wherein the printing form is provided
with process specific functional layers. i.e. one water and one ink
absorbing layer.
2. Description of the Related Technology
In offset printing processes, plates mounted on carrier cylinders
fixedly installed in a printing unit are used. Clamping segments
extended through the carrier cylinder are used to mount the plates.
The plates begin and end within the extent of these clamping
segments, accordingly the print carrier location corresponding to
an end or a beginning of the printing form is recognizable. It has
not previously been possible to produce endless images with
printing forms of this type due to the configuration of the
printing form. Furthermore, this layout permits only relatively low
rotating velocities. The carrier cylinder did not have a
symmetrical or balanced configuration. High vibratory stresses arc
generated in the printing unit by operation of unbalanced
cylinders. The unsymmetrical shape of carrier cylinders limits the
permissible web widths. In addition, the carrier cylinders were
heavy and required very carefully designed bearing supports in the
printing units. The machines were therefore expensive.
For endless printing heretofore only gravure printing and the
flexoprint process could be used. The flexoprint method only
enabled small, narrow formats to be printed in small volumes and
with an inferior quality. The gravure process requires smooth, flat
print careers. In numerous cases the gravure printing process is
not optimally suited for applications involving the production of
high quality endless prints. In particular, the gravure process is
not applicable to the printing or laminated papers, wallpapers and
gift wrappings. Furthermore, the gravure process is very expensive
and time consuming with respect to the preparation of the printing
forms required, as the printing forms must be inserted directly
into a gravure cylinder. The expensive gravure cylinders must be
available in adequately equipped printing establishments in
relatively large numbers.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved printing
process to enable rapid production of endless prints exhibiting
large widths and at an acceptable cost.
This object is attained according to the invention by providing a
sleeve shaped printing form mounted on a rotating body or cylinder.
The cylinder may be arranged so that one of its end may be accessed
so that the sleeve may be slid over the accessible end onto the
surface of the rotating printing body and fastened thereto.
According to the invention the offset printing forms and the
transfer cylinder covers are prepared in the form of sleeves, slid
onto the form and transfer cylinders and fastened thereto in a
replaceable manner. The printing form sleeves are replaced in case
of a change in the printed image. The invention advantageously
exhibits a printing form releasable from a cylinder as in offset
printing and enables printing web shaped printing carriers with
endless images of large widths at relatively high rotational speeds
of the cylinder and thus of the printing forms. The rate of
revolution may, for example, be up to 1000 rpm. Additionally, the
process enables printing on endless print carriers with relatively
high rotating body velocities and thus print carrier velocity. In
contrast to conventional gravure printing, printing shops equipped
with apparatus according to the invention do not need a large
collection of gravure cylinders. Rather, they only need a plurality
of different sleeves which may be mounted on a single rotating
body. In view of their light weight, even larger formats may be
manipulated manually.
Mounting the sleeves does not require a massive rotating body, such
as heavy printing cylinders with clamping channels. Rather,
relatively light rotating bodies such as cylinder jackets may be
used. These light rotating bodies or cylindrical jackets can be
accelerated rapidly to high rotating velocities, without danger of
introducing unacceptable vibratory stresses to the printing machine
stand due to balance deviations. Rotating bodies with this
configuration may be produced in large widths, without the risk of
excessively increasing rotating body weight technically and
economically preventing high speed operation.
A further great advantage of this process, in contrast to gravure
printing and flexoprint, is the capability of printing on both
sides of the print carrier.
Furthermore, cylinders of different widths and diameters may be
used, so that the prints are format variable within wide
limits.
Finally, the printing machines according to the invention may be
used alternatively for several direct or indirect printing
processes. For example, indirect printing such as offset and letter
set printing may be carried out by appropriate replacement of
sleeves or optionally of the cylinder jacket.
The invention further relates to an apparatus for printing on print
careers with at least one printing form mounted on a surface of a
rotating body facing the print carrier. The rotating body is
supported in rotation around a rotating axle in a stand. The
invention is particularly advantageous for printing of print
carriers in an offset printing machine with one or more printing
unit, each of which comprises a printing form, a transfer cylinder
with a damping or wetting unit, and an inking unit.
It has been possible to print only relatively narrow and short
formats at relatively low printing velocities with prior systems.
Additionally, prior machines were not capable of printing on both
sides of a print carriers. It was necessary to clamp the printing
form onto the rotating body at a certain location, whereby said
body acquired an unsymmetrical circumference. As the result of this
unsymmetrical circumference, significant vibratory stresses were
introduced into the stand of the printing machine so that in
particular in offset printing, only relatively low printing rates
could be used. Furthermore, only a relatively small format of the
print carrier could be printed.
A further object of the invention is an apparatus that can produce
endless prints at relatively high printing velocities with printing
forms having large working widths and dimensions. This object is
attained according to the invention by a printing form with a
sleeve-like configuration fixedly adhered to a rotating body and
exhibiting a surface pattern for advantageously transferring ink to
a transfer cylinder.
An apparatus according to the invention possesses a large number of
advantages resulting from the sleeve print form replaceably mounted
on the rotating body. The sleeve may be used in offset printing as
the printing form, if its surface is prepared according to the
process.
The apparatus is widely applicable in a flexible manner to various
printing techniques. It opens particularly in the offset printing
process certain entirely novel and new possibilities. It is now
feasible to print webs with endless images by this process.
Heretofore in rotating body printing methods, printing forms
clamped onto the surface of a cylinder were used. Clamping was
effected by means of clamping strips extending parallel to the axis
of the cylinder throughout its surface, so that the clamping strips
were marking the onset and the end of the printing form. No endless
images could therefore be printed by this process. The prior
application also required very heavy printing cylinders for
mounting the clamping channels and to reduce the resultant
vibrations, to which the printing forms were attached. These
printing cylinders were characterized by appreciable unbalances due
to the clamping strips present on the surface of the printing
cylinders which, especially under high velocity rotation
conditions, affected the stand by inducing vibratory stresses.
These vibratory stresses limited the speeds attainable by the
printing cylinders to a relatively low level. In contrast, sleeves
mounted on a light rotating body may be fastened so that no
unbalances are created. Even at high rotating velocities there is
no danger of vibratory stresses.
The use of sleeve-shaped print forms enables rotating body printing
operations with large operating widths. The circumference of the
print body may also extensively increase a great deal without
operational restrictions. The rotating body is preferably made of
light, high strength materials. The cylinders should be made of a
light high strength material in a tubular shape. Suitable materials
combining light weight with high mechanical strength and bending
rigidity are carbon fiber materials, silicon carbide and
beryllium.
The apparatus may be suitably arranged for printing on both sides
of a print carrier. In this manner, entirely new fields of
application are opened up for the processes.
Further details of the invention will be apparent from the
description below with reference to the drawings attached hereto,
wherein preferred embodiments of the invention are shown as
examples.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows a perspective view of a composite metal sleeve.
FIG. 2 shows a perspective view of a sleeve drawn onto a
cylinder.
FIG. 3 shows an enlarged sectional view of the rough shape of a
composite metal sleeve.
FIG. 4 shows an enlarged sectional view of a printing form of a
composite metal sleeve.
FIG. 5 shows a cross section through a sleeve coated with a layer
of rubber.
5 FIG. 6 shows a schematic view of a printing machine with the
cylinder jacket removed.
FIG. 7 shows a bearing that pivots away from the cylinder.
FIG. 8 shows a schematic view of a part of a printing machine with
a cylinder that may be pivoted around one of its ends.
FIG. 9 shows various steps of attaching the sleeve to the
cylinder.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An offset printing machine is made up of a frame, at least one
printing mechanism with one or more printing units are mounted in
stands. Each printing unit is equipped with a print form cylinder,
a transfer cylinder and a counter pressure cylinder, supported
rotatingly on.[.journals..]. .Iadd.supports, for example, journals,
displaceable journals, pivoting journals, displaceable pressure
pieces, pivoting mounts, bearing mounts, support bearings, mounting
bearings or bearing supports. .Iaddend.A gear mechanism is
connected with the journals to transfer a rotating motion produced
by a drive to the cylinders. A printing gap is provided, between
the transfer cylinder and the counter pressure cylinder, through
which a print carrier moves. In the course of its motion, the print
carrier comes into direct contact with both the transfer cylinder
and the counter pressure cylinder. In the process, patterns mounted
on the surface of the cylinder facing the transfer cylinder are
reproduced. The patterns are inked with a printing ink by an inking
mechanism distributing ink over the surface of the print cylinder.
Prior to the application of the ink, the print form is wetted by a
damping unit.
In an indirect printing process a transfer cylinder having a
yielding surface is bearingly supported in the stands between the
print form cylinder and a counter pressure cylinder. The transfer
cylinder has a flexible surface layer, such as for example rubber.
The rubber may be in the form of a replaceable sleeve. The ink is
transferred onto the rubber by the patterned cylinder and then
transferred from the flexible surface to the print carrier by the
transfer cylinder. The print carrier may advantageously be a
web.
FIG. 1 shows in a perspective view a composite metal sleeve 1
exhibiting process specific functional layers including a water and
an ink absorbing or retaining layer. The sleeve 1 comprises a
supporting metal sleeve 2, to which an intermediate metal 3 and a
surface metal 4 are applied. The supporting metal sleeve 2 may
advantageously be 0.3 mm thick and has, as indicated by its name, a
supporting function. A copper layer with a thickness of
approximately 2 to 6 microns is provided as the intermediate metal
3. The thickness is usual for offset printing plates. The surface
metal 4 is chromium with a thickness of approximately 1 to 2
microns. If the sleeve is prepared for printing as shown in FIG. 2
the copper carries the ink and the chromium the water.
As another embodiment, a light sensitive, plastic material pattern
may be deposited on the surface of cylinder 5.
Sleeve 1 may comprise a seamless elastic coating surrounding an
inner support cylinder.
In FIG. 2, the composite metal sleeve 1 is drawn onto the cylinder
5. The sleeve 1, which has a very thin wall 7, is frictionally
attached to the surface 6 of the cylinder 5. The patterns 8 are
mounted on the surface 9 of the sleeve 1 facing away from the
cylinder 5. As shown in FIG. 3 sleeve 1 is attached fixedly by
friction with its inner surface 10 facing the surface 6, so that it
cannot be displaced during printing with respect to the surface 6.
Preferably, the sleeve 1 is a metal composite. In this case, an
intermediate metal 3 surrounds the outer surface of the support
metal 2 facing away from the cylinder 5. A very thin layer of
surface metal 4 is applied to the intermediate metal 3 and the
pattern 8 (see also FIG. 4) is worked into the surface metal 4.
Nickel or steel may be used as the support metal 2. Copper is
usually chosen as the intermediate metal 3 and chromium is applied
to it as the surface metal 4. Such single or composite metal forms
are well suited for use in the offset printing process.
The sleeve 1 may be fastened in a number of ways to the surface 6
of the cylinder 5. For example, an air cushion 51 may lift the
print form for mounting or upon uniform heating of the sleeve 1, it
expands so that it may be pushed onto the surface 6 of the cylinder
5. During subsequent cooling the sleeve 1 contracts and thereby
attaches itself firmly to the surface 6 and is held by frictional
forces. Such a shrink fitting of the sleeve 1 is favorable because
the patterns 8, particularly in the case of single metal forms, are
applied by a sensitizing lacquer, burned into the surface 9 of the
sleeve 1 at a temperature of approximately 200.degree. C. During
this burning of the sensitizing lacquer the sleeve 1 is heated to a
temperature suitable for shrink fitting.
Alternatively as shown in FIG. 9, sleeve 1 may be fastened to
cylinder 5 by expanding sleeve 1 with pressure from a pressure
medium 50. The sleeve is then moved over cylinder 5 and allowed to
relax.
FIG. 5 shows a sleeve 1a coated with a layer 11 of rubber in
cross-section. The rubber layer 11 surrounds a support metal sleeve
2. The support metal sleeve 2 may be a metal tube with a thickness
of about 0.3 min. The rubber cover 11 may be approximately 1 to 5
mm thick.
To change the sleeve 1, the cylinder 5 may either be removed
completely from the stands 12, 13 or preferably remain in part
within the stands 12, 13.
FIG. 6 illustrates the cylinder in the form of a cylinder jacket 20
which may be removed from the stands 12, 13 by retraction on
longitudinally displaceable bearings 21, 22. The bearings 21, 22
are supported in the stands 12, 13 so that they may be displaced
longitudinally in the direction of the cylinder. They project with
the pressure pieces 23, 24 of the cylinder jacket 20. The pressure
pieces 23, 24 are positively guided in the recesses 25, 26.
To remove the cylinder jacket 20, the pressure pieces 23, 24 are
moved in the direction of their adjacent stands 12, 13 and thereby
withdrawn from the recesses 25, 26. The cylinder jacket 20 can now
be removed from the stands 12, 13 and the sleeve may be replaced.
The cylinder jacket 20 is then lowered between the stands 12, 13 to
the bearings 14. Subsequently, the pressure pieces 23, 24 are moved
in the direction of the cylinder jacket 20, until they positively
engage the recesses 25, 26 and align them between the stands 12, 13
so that the accurate circular rotation of the cylinder jacket 20 is
assured.
It is also possible to replace the sleeve 1 on a cylinder 5 without
removal from the stands 12, 13 as illustrated in FIG. 7. The
cylinder may be supported at one end 30 in a cantilever manner in
the stand 12 and guided at its other end 31 in a pivoting bearing
32. This pivoting bearing 32 is supported by a pivot bearing 33 on
the stand 13 and may be swivelled from the stand 13 to face away
from the cylinder 5. Following the swiveling of the pivoting
bearing 32, the stand 13 exhibits a recess 34 having a
cross-section larger than the cross-section of the sleeve 1. The
sleeve 1 may be drawn off the cylinder 1 and replaced through means
of this recess 34. Following replacement of the sleeve 1, the
pivoting bearing 32 is swivelled back in the direction of the
cylinder 5, so that the end 31 of the cylinder 5 is guided within
the pivoting bearing 32.
The embodiment illustrated in FIG. 8 provides for a pivoting
attachment of the cylinder 5 at one of its ends 40 to a bearing 41.
A pivot bearing 42 is provided between the bearing 41 and the end
40. The cylinder 5 may be swivelled transversely to its
longitudinal axis around the pivot bearing 42. The cylinder 5 is
equipped with a recess 44 at end 43 located opposite to the pivot
bearing 42. A pressure piece 45, rotatingly supported in the stand
13, projects into recess 44. The pressure piece 45 is
longitudinally displaceable relative to the cylinder 5. The
pressure piece engages the recess 44 when the cylinder is in the
printing position. The pressure piece 45 is displaced in the
direction of the stand 13 to enable the cylinder 5 to swivel around
the pivot bearing 42. The pressure piece is thereby moved out of
the recess 44, so that the cylinder 5 is freely movable at its end
43 adjacent to the stand 13. The cylinder may be swivelled around
the pivot bearing 42 until it protrudes out of the area of the
stand 13. The sleeve 1 may then be pulled off the cylinder 5 and
replaced. Following the replacement of the sleeve 1, the cylinder 5
is pivoted back into the printing position. In the printing
position the pressure piece 45 may be displaced toward and locked
into the recess 44 in the longitudinal direction. The cylinder and
the new sleeve 1 is then ready for operation. The process of
replacing the sleeves 1 has been described with reference to FIGS.
6 to 8 for the print form sleeve 1. The same process steps are
applicable to the transfer sleeve 1a with a rubber cover 11,
together with the same design principles.
* * * * *