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Description  |
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The invention relates to a device, in the form of a magazine, for supplying
printing plates to a plate cylinder of a printing press, in particular for
the automatic or semi-automatic changing of printing plates, with a
plate-supplying apparatus.
A device of the initially mentioned kind is known from European patent
application 0 435 410. The purpose of said device is to automate the
changing of printing plates. The magazine holds old, used plates. For
removal, the used printing plate is released from the plate cylinder at
one end and is then--through appropriate rotation of the plate
cylinder--partially inserted into the magazine. Subsequently, the other
end of the printing plate is released by the tensioning device of the
plate cylinder and the entire printing plate is introduced into the
magazine with a plate-removing apparatus. Subsequently, a new printing
plate to be used is taken from the magazine by means of the
plate-supplying apparatus. First, one end of the printing plate is
inserted into the corresponding clamping device of the plate cylinder,
where it is clamped, and then--through rotation of the plate cylinder--the
printing plate is removed completely from the magazine and is drawn around
the outer cylindrical surface of the plate cylinder. Then, the other end
of the printing plate is clamped and the plate is tensioned in the
circumferential direction. The supplying of printing plates may be
disrupted if, when a new printing plate is removed, at least one other of
the new printing plates held in a pile in the magazine unintentionally
changes its position.
SUMMARY OF THE INVENTION
The object of the invention is to create a device of the initially
mentioned kind, the device permitting the operationally reliable supplying
of printing plates while being of simple construction and small design.
The object of the invention is achieved in that the plate-supplying
apparatus comprises a plurality of distributed, consecutively activatable
(second) holding means for the printing plate.
In order to supply a new printing plate to be used, the printing plate is
taken from the cassette of the magazine, supplied to the plate cylinder
and clamped thereon. This operation takes place fully automatically or,
alternatively, semi-automatically using the plate-supplying apparatus,
with the non-simultaneous, but preferably consecutive activation of the
second holding means over the length of the yet to be used printing plate
having the advantage that the printing plate to be used can be lifted
perfectly from the pile of new printing plates in the cassette,
without--thanks to the flatness of the positioning--any further printing
plate being lifted or slid out as a result of the formation of a vacuum.
Preferably, the second holding means are in the form of activatable second
suction elements.
It is advantageous if the second holding means are disposed on a second
carriage, said carriage being movable along a second guide. Further
disposed inside the magazine is a sensor which monitors the printing plate
to be used, particularly the rear edge thereof, for correct supplying to
the plate cylinder.
During the plate-supplying operation, the second holding means associated
with the front edge of the new printing plate release the printing plate
while it is more or less in the clamping position or hold it so loosely
that the printing plate is displaceably held before the printing-plate
front edge is clamped on the plate cylinder. The purpose of this is so
that the printing plate can be better aligned during clamping. After the
front edge has been clamped, tile plate cylinder rotates and pulls the new
printing plate completely out of the cassette of the magazine. Both for
the alignment of the printing plate and also for its removal from the
cassette, the suction elements serving as the holding means may, for
example by means of a bypass, be provided with such a weak vacuum that the
printing plate slides on the suction elements.
As the angled printing-plate rear edge approaches a row of suckers, said
row is taken out of operation and brackets ensure that the edge slides
past. By the time the printing plate has been drawn in so far that the
last row of suckers must be passed, it exhibits such a stiffness that, in
order to prevent a collision, said holding means are adapted, while the
printing plate is being supplied to the plate cylinder, to be moved
controllably transversely with respect to the plane of the printing plate,
with the result that they can be passed correctly, preferably without
collision, by the preferably angled rear edge of the printing plate.
Furthermore, it is advantageous if the magazine comprises at least one
pressing-on element movable by activation radially with respect to the
plate cylinder, particularly a pressing-on roller, for introducing the
rear edge into a clamping device of the plate cylinder, with the result
that, through the closing of the clamping device, the printing plate can
then be fixed and clamped.
Moreover, it is advantageous to employ a pressing-down device, said
pressing-down device engaging the yet to be used printing plates remaining
in the cassette transversely with respect to the planes thereof, in order
to prevent their tipping out from the cassette. Otherwise, such
tipping-out might occur particularly when, after an automatic plate change
has been performed, the magazine is swiveled back into its vertical
position.
It has already been explained hereinbefore that the lifting of a new
printing plate from the pile of printing plates inside the cassette is
effected not simultaneously over the whole surface area, but is staggered
in such a manner that air is able to get between the plates, in order to
prevent the printing plates from "sticking together". For example,
suction-gripping by the rear, upper row of suckers may be effected first,
followed by the middle row and finally by the lower row of suction
elements. Moreover, it may preferably be provided that a cassette holding
the printing plates to be used--said cassette being insertable into the
magazine--comprises spacers, said spacers being disposed between adjacent
printing plates. Said spacers prevent a vacuum from forming between the
individual printing plates. They may be in the form of plastic tabs.
Preferably, they are adapted to be fixed on the cassette in the locking
seat. Consequently, when a cassette is being filled, a spacer (or a
plurality of spacers) is first clipped into the cassette in such a manner
that it is disposed on the surface of an inserted printing plate. Only
then is a further new printing plate inserted into the cassette. The
spacers are so flexible that they yield when a below-lying printing plate
is removed.
The invention is illustrated on the basis of a specimen embodiment with
respect to the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a printing unit of a printing press in a schematic
representation with a magazine in the starting position;
FIG. 2 shows the magazine from FIG. 1 in a center position;
FIG. 3 shows the magazine in the plate-changing position while a new
printing plate to be used is supplied to the plate cylinder of the
printing press;
FIG. 4 shows a representation according to FIG. 3, with, however, the
printing plate already having been clamped onto the plate cylinder;
FIG. 5 shows the return of the magazine into the starting position;
FIG. 6 shows the movement to the center position in order to accept a used
printing plate;
FIG. 7 shows the magazine in the plate-changing position during acceptance
of the used printing plate;
FIG. 8 shows a representation according to FIG. 7, with, however, the
printing plate already being completely in a cassette of the magazine;
FIG. 9 shows the magazine once again in the starting position;
FIG. 10 shows a longitudinal section through the magazine;
FIG. 11 shows a longitudinal section through the magazine according to FIG.
10, but in a different plane;
FIG. 12 shows a cross section through the magazine;
FIG. 13 shows a schematic view in the longitudinal section during the
supply of a used printing plate to the magazine;
FIG. 14 shows a representation according to FIG. 13, but with the printing
plate introduced further;
FIG. 15 shows the magazine in the longitudinal section with the printing
plate completely introduced;
FIG. 16 shows a representation according to FIG. 15, but with the front
edge of the printing plate being introduced into a cassette of the
magazine;
FIG. 17 shows a cross section through the magazine in the region of a
plate-removing apparatus; and
FIG. 18 shows a longitudinal section through the cassette.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to provide for automatic or semi-automatic changing of printing
plates--that is, to remove an old, used printing plate and then to supply
a new printing plate to be used to the plate cylinder 1 of a printing unit
2 of a printing press 3--the printing unit 2 comprises a device in the
form of a magazine 4. The magazine 4, which, in the case of a printing
press 3 with a plurality of printing units 2, is provided on each printing
unit 2 of the printing press 3, may also be used merely to supply a new
printing plate to be used or merely to remove an already used printing
plate (FIG. 1 to 9).
In FIG. 1, the magazine 4 is in its starting position (vertical position).
In this idle position, the magazine 4 is secured (locked) against tilting.
Normal printing-press operation (printing mode) is possible only with the
magazine 4 in this lower, vertical position.
The magazine 4 comprises two holding shafts 5 and 6, into which cassettes 7
and 8, respectively, are insertable from above (FIG. 1). The cassette 7 is
used to hold old printing plates which have already been used in the
printing press 3. The cassette 7 is of such design that it is capable of
holding a plurality of, for example five, used printing plates. Said
printing plates form a printing-plate pile inside the cassette 7; that is,
the individual printing plates are in flat contact with one another. The
cassette 8 is used to hold new printing plates that are yet to be used.
It, too, is capable of holding a plurality of, particularly five, printing
plates simultaneously, with, once again, said printing plates being in
flat association with one another. In order to remove the used printing
plates, it is thus merely necessary to withdraw the cassette 7 out of the
holding shaft 5. Once outside of the printing press 3, the cassette 8 can
be furnished with new printing plates yet to be used. Once this has been
done, the cassette 8 is inserted into the holding shaft 6 of the magazine
4, with the result that it is available for supplying the plate cylinder 1
of the corresponding printing unit 2.
Described hereinbelow are the individual positions of the magazine 4 which
are assumed for the removal and/or supply of printing plates. If the plate
cylinder 1 is to be supplied with a new printing plate 9, the magazine 4
moves--as shown in FIG. 2--vertically upwards into a center position and
then--as shown in FIG. 3--swivels into an oblique position (approximately
45.degree., for example). By means of a plate-supplying apparatus (still
to be described in greater detail) of the magazine 4, the printing plate 9
to be used is then supplied to the plate cylinder 1 and is clamped thereon
(FIG. 4). Subsequently, the magazine 1 then swivels back into its vertical
position and is then lowered again into the lower position (starting
position) as shown in FIG. 5.
The printing process can now be carried out. When the printing job has been
performed, the printing plate 9 must be removed from the plate cylinder 1.
For this purpose, a lifting device, in turn, lifts the magazine 4 into the
center position (FIG. 6). Subsequently, as shown in FIG. 7, the magazine 4
is swiveled into the oblique position and--through releasing of the plate
rear edge and backward rotation of the plate cylinder 1--the used printing
plate 10 is partially inserted into the magazine 4 (FIG. 7).
As shown in FIG. 8, the used printing plate 10 is then pulled completely
into the cassette 7 by a plate-removing apparatus (still to be described
in greater detail) of the magazine 4. Next, the magazine 4 is again
swiveled into its vertical position and then--as shown in FIG. 9--is
lowered into the starting position.
Of course, it is also possible to combine the removal and supply of
printing plates in order to effect the changing of printing plates. This
means that, in the oblique position, a used printing plate 10 is first
accepted by the magazine 4 and a new printing plate is then supplied to
the plate cylinder 1. Once this has been done, the magazine 4 swivels back
into the vertical and is lowered into the starting position.
Hereinbelow, the design of the magazine 4 is to be described in greater
detail with reference to FIG. 10 to 12.
For graphical reasons, the magazine 4 is shown in FIG. 10 and 11 in a
horizontal position in relation to the side edges of the drawing sheet. It
should, however, be pointed out that the positions shown in FIG. 10 and 11
correspond to the oblique positions shown in FIG. 3, 4, 7 and 8.
The magazine 4 is of layered construction. It comprises an outer layer 11,
which holds the cassette 7. Accommodated in a following layer 12 is a
plate-removing apparatus 13, which is associated with the aforementioned
cassette 7. The cassette 8 is disposed in a following layer 14. A further
following layer 15 holds a plate-supplying apparatus 16, which cooperates
with the printing plates 9 of the cassette 8.
The plate-removing apparatus 13 comprises first holding means 17, which are
in the form of activatable first suction elements 18. The suction pads 19
of the first suction elements 18 can be extended towards the printing
plates 10 (for the sake of clarity, only one printing plate 9/10 is shown
in each of FIG. 10 and 11). The first suction elements 18 are disposed on
a first carriage 20, which is adapted to be moved along a first guide 21.
As shown in FIG. 17, the guide 21 comprises two spaced-apart,
parallel-extending guide parts 22, which are in the form of guide rods 23.
The guide rods 23 are encompassed with little play by guide parts 24 of
the first carriage 20.
The first carriage 20 is adapted to be moved along the first guide 21 by
means of a driving apparatus 25. The driving apparatus 25 comprises a
fixed, non-ferromagnetic tube 26 (an aluminium tube, for example), which
extends from the top side to the bottom side of the magazine 4. Situated
inside the tube 26 is a magnetic piston 27, which is adapted to be moved
backwards and forwards inside the tube 26 by means of a pressure medium in
addition to being positionable in desired positions. Situated on the first
carriage 20 is a ferromagnetic component 28 which is in the form of a
steel ring 29. Consequently, a movement of the magnetic piston 27 has the
effect that the steel ring 29 and therefore the carriage 20 are moved
through the intermediary of the magnetic field. Such a design provides a
flexible coupling and, moreover, the carriage is movable from a position
at the extreme top in the magazine 4 (shown by solid lines in FIG. 10)
into a position at the extreme bottom (shown by broken lines in FIG. 10).
As shown in FIG. 17, a suction element 18 is disposed on either side of the
driving apparatus 25. Each suction element 18 is attached to a lever 30,
which is adapted to be swiveled towards the printing plate 10 by means of
a hinge 31 (FIG. 13). The position of the levers 30 is determined by a
forced-control device 32 (see also FIG. 13), which is formed by a roller
33 connected to each lever 30, said roller 33 running in a location-fixed
guide rail 34. Each guide rail 34 comprises in the upper region of the
magazine 4 a bevelled section 35 (FIG. 13), with the result that, with the
carriage 20 moving into an upper position, the rollers 33 contact the
bevelled sections 35 and thereby swivel the levers 30 and thus the suction
elements 18 towards the printing plate 10. Springs 115 serve to return the
lever 30 and to make the rollers 33 contact the bevelled sections 35.
Disposed on opposite sides in the lower region of the magazine 4 are
actuatable holders-down 36, which serve to engage the printing plate 10 in
said region. Furthermore, guide rollers 37, 38 and 39 are disposed in the
lower region of the magazine 4.
Hereinbelow, there is a functional description of the removal of a used
printing plate 10 from the plate cylinder 1 into the cassette 7 of the
magazine 4. For this purpose, first of all, the magazine 4 is--as shown in
FIG. 6 and 7--brought into the required oblique position. Subsequently, a
rear-edge clamping device 40 of the plate cylinder 1 opens and releases
the there-clamped, angled printing-plate rear edge 41. Owing to the
inherent elasticity, the rear end of the printing plate 10 consequently
strikes against the guide roller 37 (FIG. 13). Subsequently, through
backward rotation (arrow 42) of the plate cylinder 1, the printing plate
10 is inserted into the cassette 7 of the magazine 4. The guide rollers
37, 38 and 39 assist with the introduction of the rear-edge end of the
printing plate 10. Guide rails 116 may be provided, said guide rails 116
sliding in cutouts of the printing-plate rear edge 41. Said introduction
is shown by a dotted line in FIG. 13 and by an unbroken line in FIG. 14.
When approximately one-third of the printing plate 10 has been inserted
into the magazine 4, the suction elements 18 of the carriage 20 (the
carriage 20 being in the lowermost position inside the magazine 4) are
activated; that is, the suction pads 19 move towards the printing plate 10
to be held and firmly adhere by suction to the printing plate 10. Next,
with simultaneous further backward rotation of the plate cylinder 1, the
carriage 20 moves into its upper position, as a result of which the
printing plate 10 is pulled completely into the magazine 4, with the front
edge 44 of the printing plate 10 also being unclamped. When the carriage
20 enters the upper end region of the magazine 4, the rollers 33 contact
the bevelled sections 35 and swivel the levers 30, with the result
that--as shown in FIG. 15--the angled printing-plate rear edge 41 comes
under a holding edge 43 of the cassette 7. Subsequently, the holders-down
36 press down the printing plate 10 in the region of its front edge 44
(FIG. 16), with the result that the front edge 44 comes to lie at a lower
position than a holding edge 45 of the cassette 7. Through the force of
gravity and/or through movement of the carriage 20, the front edge 44 is
then brought under the holding edge 45 through pulling-down of the
printing plate 10. Consequently, the printing plate 10 is safely disposed
in the cassette 7. Particularly if a plurality of already used printing
plates 10 are to be accommodated in the cassette 7, it is necessary for
the last-inserted printing plates 10 to be pulled down by means of the
carriage 20 and to be held by the holders-down 36, so that they come under
the holding edge 45, since, owing to relatively great stresses at the
start of the printing plate, the force of gravity alone is no longer
sufficient to move the printing plates 10 into said position.
The removal of the used printing plates 10 from the magazine 4 is
accomplished in simple manner in that the cassette 7 is withdrawn from the
associated holding shaft 5.
FIG. 18 shows a longitudinal section through a cassette 7. The cassette 7
comprises a base 46, which is adjoined by U-shaped upper and lower edge
regions 47, 48. The upper edge region 47 comprises a U-shaped leg 49 and
the lower edge region 48 comprises a U-shaped leg 50, which forms the
holding edge 45. The length x of the U-shaped leg 49 is greater than the
length y of the U-shaped leg 50. The clear distance between the ends of
the U-shaped legs 49 and 50 is selected such that a printing plate 10 to
be inserted is first slid under the U-shaped leg 49 and is then swung into
the interior of the cassette 7, with the front edge 44 passing the
U-shaped leg 50. Subsequently, the printing plate 10 is then displaced in
such a manner that its front edge 44 passes under the U-shaped leg 50,
without, however, the locating action of the U-shaped leg 49 being
lost--thanks to the greater length of the U-shaped leg 49.
Consequently, the printing plate 10 is safely accommodated inside the
cassette 7. The procedure is similar when removing a printing plate 9 from
a cassette 8, insofar as use is made also of a cassette with locating
edges. It is, however, also possible to use a design without locating
edges as the cassette 8.
Each cassette 7 or 8 comprises in its upper region a handle 51 in order to
facilitate insertion and removal from the respective holding shaft 5 or 6
of the magazine 4. In addition, the handle 51 also makes it easier for the
corresponding cassette 7 or 8 to be transported to the printing press.
Furthermore, each cassette 7 or 8 is provided with a marking, particularly
a colour marking (this may be disposed, for example, on the handle 51),
said marking relating to the respective printing unit 2 of the printing
press 3. For example, the handle 51 may be of a colour corresponding to
the printing ink of the respective printing unit 2. Unambiguous
identification is made possible in this manner.
Reference may be made already at this point to a special feature of the
cassette 8 containing the new printing plates 9 yet to be used, although
the removal of the printing plates 9 from the cassette 8 will be discussed
at a later point hereinbelow. If there is a plurality of printing plates 9
piled one on top of the other inside the cassette 8, then it is possible,
when the uppermost printing plate 9 is removed, for a vacuum to be formed
with respect to the following printing plate 9. This may result in two
printing plates being removed simultaneously by mistake owing to the fact
that they "stick together". To prevent this, a special removal technique
is implemented and will be discussed in greater detail hereinbelow;
moreover, it is possible to provide spacers between the individual
printing plates 9, with the result that the formation of a vacuum is
prevented. The spacers are preferably in the form of plastic tabs. These
can be clipped preferably into locking seats in the edge regions. An
advantageous further development of the invention provides that the
spacers are in the form of two rows of individual tabs, with, when the
printing plates are being inserted, a tab being placed between every two
printing plates on both sides. It is advantageous for said tabs to be
disposed in the region of the front row of suckers, which goes into action
first. Consequently, when a cassette 8 is being furnished with printing
plates, spacers are first of all clipped in position before a further
printing plate 9 is laid on a printing plate 9 already in the cassette 8.
The spacers are so flexible that they yield when the printing plate below
is removed.
If, after the removal of a printing plate 10, a new, as yet unused printing
plate 9 is to be clamped immediately onto the plate cylinder 1, then the
magazine 4 remains in its oblique position and a new printing plate 9 is
taken from the cassette 8. This is accomplished by means of the
plate-supplying apparatus 16.
In order for a printing plate 9 from the cassette 8 to be supplied to the
plate cylinder 1 by means of the plate-supplying apparatus 16, the
magazine 4 is--as mentioned hereinbefore--in its oblique position in which
support rollers 52 are supported on cylinder bearers 53 associated with
the plate cylinder 1. The plate-supplying apparatus 16 comprises on a
second carriage 54 second holding means 55, which are likewise in the form
of activatable suction elements 56 (second suction elements). As shown in
FIG. 10 and 12, the suction elements are each disposed spaced-apart in
rows in groups of four, with three rows being provided on the second
carriage 54. It is also possible for the lower row of suction elements 56
nearest to the plate cylinder 1 to be equipped with four suction elements
56 and for the other rows each to be provided with three. The suction
elements 56 disposed in the lower row associated with the plate cylinder 1
are attached to levers 57, which are adapted to be swiveled about shafts
58. Pneumatic cylinders 59 are provided for the actuation of the levers
57. Furthermore, the levers 57 are subjected to the force of a spring 60.
Disposed in the upper region of the magazine 4 is a preferably optical
sensor 61, which monitors the position of the associated printing plate 9,
particularly the position of the rear edge 41 thereof. Disposed between
the upper and middle rows of suction elements is an activatable
pressing-down device 62 for engagement of the printing plates 9. In
addition, the magazine 4 comprises at its lower end a displaceable
pressing-on element 63, which is in the form of a pressing-on roller 64
displaceable radially with respect to the plate cylinder 1.
The second carriage 54 is movable along a second guide 66 (FIG. 12) by
means of a piston/cylinder unit 65. The second guide is formed by fixed
profile rails 67, in which run guide rollers 68 of the carriage 54.
For the supplying of a printing plate 9, the lowermost suction elements 56,
associated with the plate cylinder 1, may first of all come into
operation, with the levers 57 being in their non-deflected positions.
Thereafter, the suction elements 56 of the middle row of suckers and then
the suction elements 56 of the upper row of suckers are activated. A
different sequence, such as first the middle row and then the row at the
edge, is conceivable. The non-simultaneous, but consecutive activation of
the rows of suction elements ensures that the uppermost, new printing
plate 9 is lifted in such a manner that no vacuum or only a very small
vacuum is formed with respect to the further printing plate 9 below. This
guarantees that only one printing plate 9 is lifted. As for the rest, the
aforementioned spacers (plastic tabs) may be disposed between the
individual printing plates 9, which additionally counteracts the formation
of a vacuum. When the printing plate 9 has been lifted, the carriage 54 is
pushed towards the plate cylinder 1 by means of the piston/cylinder unit
65. The front edge 44 of the printing plate 9 enters the front-edge
clamping device 69 of the plate cylinder 1, which was appropriately
positioned beforehand. During the above-depicted advance of the carriage
54, the angled printing-plate rear edge 41 slides through under the sensor
61, which registers the correct transport of the printing plate 9. During
the transport of the carriage 54, a bypass in the air supply to the
suckers of the suction elements 56 is activated, since a strong suction
air is required only for the suction-gripping of the printing plate 9.
After the carriage 54 has almost reached its outermost position facing the
plate cylinder 1, the suckers of the lowermost and middle rows of suction
elements 56 are rendered pressureless or are provided only with a weak
vacuum; the printing plate 9 is therefore held only by the uppermost row
of suckers. The purpose of this is so that the printing plate 9 can be
better aligned. Subsequently, the front-edge clamping device 69 is closed,
with the result that the front edge 44 of the printing plate 9 is firmly
clamped. Next, the plate cylinder 1 rotates in the forward direction,
pulling the printing plate 9 onto its outer cylindrical surface. Thanks to
the bypass, the suction elements are provided only with a weak vacuum,
with the result that they still hold the printing plate, but the printing
plate can still be displaced on the suction elements through the rotation
of the plate cylinder. Before the printing-plate rear edge passes the two
upper rows of suckers, the latter are rendered pressureless and brackets
70 ensure that the angled rear edge slides past the suction elements
without collision. Owing to its proximity to the plate cylinder 1, the
printing plate 9 is relatively rigid in the region of the lower row of
suction elements 56, with the result that, for the passage of the angled
printing-plate rear edge 41, a lever 57, in the form of a plate with hinge
and carrying the entire row of suckers, or a plurality of levers 57 are
swivelled into their positions shown in FIG. 10 by means of one or more
cylinders 59, with the result that the printing-plate rear edge 41 is able
properly to pass the row of suckers. Subsequently, the pressing-on roller
64 is moved radially towards the plate cylinder 1, as a result of which
the angled printing-plate rear edge 41 is pressed into the rear-edge
clamping device 40 of the plate cylinder 1. The rear-edge clamping device
40 closes and then tensions the printing plate through appropriate
displacement in the circumferential direction of the plate cylinder 1.
Thereafter, the carriage 54 is moved back to its original position in
order, at the appropriate time, to grip the next printing plate 9.
The device moves back into its starting position in that the cylinders 59
are rendered pressureless, with the result that the springs 60 are able to
ensure that the lever(s) 57 return to their original positions.
Subsequently, the pressing-down device 62 comes into action, ensuring that
the remaining printing plates 9 remain properly in the cassette 8 and are
unable to tip out, particularly when the magazine 4 is swiveled back into
its vertical position.
FIG. 10 shows that the upper and middle rows of suction elements 56 are
associated with elastic brackets 70. The elasticity of the brackets 70
permits the suction-gripping of the printing plate 9 that is to be used;
that is, the brackets 70 do not disrupt this operation. As soon as the
suction elements 56 no longer have any vacuum and, to that extent, the
printing-plate rear edge 41 slides past the suction elements 56 during the
supplying of the printing plate 9, the brackets 70 ensure that the angled
printing-plate rear edge 41 does not catch on the suckers of the suction
elements 56.
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