Note: Descriptions are shown in the official language in which they were submitted.
~3(~Z~
1 FILM AND PLATE REGISTRATION SYSTEM FOR
FLEXOGRAPHIC PRINTING PROCESS
Field of the Invention
The present invention relates to apparatus for
mounting printing plate~ on cylinders, and in
particular, to regiRtration and mounting means for
affixing flexible printing plate~ on cylinder~.
Back~round of the Invention
When flexible printing plates, such as
photopol~mer plate~, are mounted to print cylinders,
a high degree o accu~acy of the mounting o~ the
plate to the cylinder is necessary so that the plate
image is properly aligned, or registered. Extremely
accurate standards must be followed in affixing the
plate to the cylinder or else the images on the
fini~hed work will be blurred and overlap.
One method of registration of the printing plate
to the plate cylinder is by exacting hand worX,
however, this type o~ lay up is extremely time
cons~ming and expensive.
To assist in applying the printing plate to the
cylinder, some methods employ plate drills which form
precisely positioned holes in the plate. The work is
pinned through the holes to a mountiny bar which is
then used to connect tha plate to the plate cylinder.
The CYREL Registration System of Dupont, like
the present sy~tem, is directed toward a particular
* Trade-mark
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1 film and plate drill apparatus and a registra-tion bar
which fits on the plate cylinder and is used to apply
the printing plate to the cylinder. This system is
complex and expensive and the present system provides
advantages of speed and economy over the CYREL
Registration System.
Although the present appara~us can be used in
conjunction with any flexible printing plate, it is
particularly advantageously used in connection with
photopolymer printing plates, such is made by Dupont
and other manufacturers.
Objects of the Invention
The objects of the present invention are: to provide
a plate drill apparatus which i5 configured to drill
the necessary holes in a flexible printing plate; to
provide such a plate drill apparatus which is
; adjustable to accommodate various sizes of printing
plates; to provide such a plate drill apparatus which
includes a positioning means which aids in drilling
the plate in a selected alignment; to provide a
registration table adaptable to different sizes of
plates: to provide such a registration table which is
adaptable to mount printing plates to various sizes
of print cylinders; to provide such a registration
table which fits the plate to a cylinder wi-thout
~ requiring any adaptation to the plate to a cylinder;
; and to provide such a plate registration system which
is relatively inexpensive and particularly well
adapted for the intended purpose.
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1 According to the present invention there is provided
a regis-tration -table for mounting a flexible printing
pl.ate to a cylinder and comprising: (a) a table
having an upper, planar work surface; (b) guide means
along a front edge of said work surface and for
contacting the surface of a plate cylinder, (c) a
plate mounting bar extending across said work surface
and positioned parallel to said guide means, (d~
means for removably securing a flexible printing
: 10 plate to said plate mounting bar; and (e) whereby
when said plate cylinder is positioned against said
guide means and said printing plate secured to said
plate mounting bar, said plate may be rolled on to
said plate cylinder in registration therewith.
Also according to the present invention there is
provided a registration table for mounting a flexible
printing plate to a cylinder and comprising: (a) a
table having an upper, planar work surfa~e; (b) guide
means extending across a ront edge of said work
surface and for contacting the surface of a plate
cylinder; (c) a plate mounting bar extending across
said work surface and slideably affixed thereto by
slide means positioning said plate mounting bar
; parallel to said guide means for sweeping said plate
mounting bar across said work surface parallel to
said guide means (d) means for removably securing a
flexible printing plate to said plate mounting bar,
and ~e) whereby when said plate cylinder .i5
positioned against said guide means arld said printing
plate secured to said plate mounting bar, said plate
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28379-1
mounting bar is swept toward said plate cylinder and said
printing plate affixed to said cylinder in xegistration
therewith.
Also according to the present invention there is
provided a registration table mounting a flexible printing
plate to a cylinder and comprising: (a~ a table supported on
legs and having an upper, planar work surface ~ith opposite,
parallel side edges and a front edge perpendicular thereto,
said work surface being slan~ed downwardly; (b) a guide rod
mounted to said work surface adjacent and outward of said front
edge, and having ro].lers to contact the surface of a plate
cylinder; (c) a plate mounting bar extending across sald work
surface and slideably affixed thereto by slide means including
opposite rails mounted to said side edges and positioning said
plate mounting bar parallel to said guide rod for sweeping said
plate mounting bar across said work surface parallel to said
guide rod; (dj pins for removably securing a flexible printing
plate to said plate mounting bar; and (e) whereby when said
plate cylinder is positioned against said guide rod and said
printing plate pinned to said plate mounting bar, said plate
mounting bar is swept toward said plate cylinder and said
printing plate adhered to said cylinder in registration
therewith.
Other objects and advantages of this invention will
become apparent from the following description taken in
connection with the accompanied drawing~ wherein are set forth,
by way of illustration and example, certain embodiments of this
invention.
~3~2~6I 2~379-1
Description of the ~rawin s
Figure 1 is a schematic view of the steps taken in
the process of preparing and moun~ing a pri:nting plate to a
plate cylinder.
3~2~
em-bo~ying -the present~ ~e~n.
Fig. 2 is a perspective view of a drill table
embodying the present invention.
Fig. 3 is a plan view of the drill table.
Fig. 4 is a plan view of a registration table
embodying the present invention.
Fig. 5 is a side elevational view of the
registration table with a plate cylinder positioned
next to it.
Fig. 6 is a side elevational view of the
registration table showing tilt.
Description of the Preferred and Alternate Embodiments
As required, detailed embodiments oE the present
invention are disclosed herein, however, it is to be
understood the disclosed embodiments are merely
exemplary of the invention which may be embodied in
various forms, therefore, specific structural and
functional details disclosed herein are not to be
interpreted as limiting, but merely as a basis for
the claims and as a representive basis for teaching
one skilled in the art to variously employ the
present invention in virtually any appropriately
detailed structure.
Referring to the drawings in more detail:
The reference numberal 1, Fig. 2, generally
indicates a drilling apparatus embodying the present
invention. The reference numeral 2, Fig. 4,
generally indicates a registration table, also
embodying the present invention. Both the drilling
'~L3~2016~
1 apparatus 1 and registration table 2 are used in the
process for preparing and mounting a printing plate
to a plate cylinder and find particular use in the
flexographic printing process.
Referring to Fig. 1, in the flexographic
printing process, a p~otographic negative is made of
the work to be printed and the negative combined with
an unexposed or undevelopea printing plate is taXen
to t'ne drill table, or the drilling apparatus 1.
There, the plate and the photographic negative are
drilled and then taken to an exposure unit which, in
the flexographic printing process wherein a photo-
polymer plate is used, the exposure unit uses a vacuum
pressure -to tightly engage the photographlc negative
to the plate and then expose the negative and the
plate so the image of the work is transferred from
the negative to the photopolymer plate. After
exposure, the undeveloped plate is then taken to a
processor unit which, through a series of solvent
washes, removes the unimaged portions of the printing
plate to a depth selected on the basis of processing
time. The photopolymer plate, with the image formed
thereon, is now taken to a dryer unit which dries the
sticXy plate material. In the next step, the plate
is taken to a finishing table where various acid bath
chemicals smooth the finish of the plate. Finally,
the plate is transferred to a registration table
where it is registered and precisely applied to a
print cylinder. The cylinder is then taken to the
press facility for operations.
~3s.~
1 Referring in detail to Figs. 2 and 3, the
drilling apparatus 1 is in the form of a drilling
table 4 which includes front and rear sets of legs 5
and 6 and an upper connecting frame work 7, such as
of square tube steel construction. The table 4
includes front and rear platforms 9 and 10, each with
planar worX surfaces.
Between th~ front and rear platforms 9 and 10 is
a track 11 formed of parallel, spaced rails 13 and
14, such as also of the square tube construction, and
which forms a mountlng means for plate drills 16 and
17. In the illustrated example, each of the plate
drills 16 and 17 is a commercially available drill
head and includes a hollow bit 18 and a rotatable
handle 19 for lowering the drill bit 18 to the
printing plate. The plate drills 16 and 17 are
connected by slides to the rails 13 and 14 and lock
means, such as removable pins 21, are selectively
connectable to holes spaced alon~ the length of the
rails 13 and 14 for setting the position of each of
the plate drills 16 and 17.
The plate drills 16 and 17 are movable toward
and away from each other on the rails 13 and 14 to
accommodate various widths of a plate material, the
width of which is governed by the size of the plate
cylinder to which the plate is to be mounted.
Perferably, a plate positioning bar 23 extends
across the front platform 9 and has opposite ends
mounted in side tracks 24 and 25 for even, parallel
movement ~oward and away from the track 11 containing
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l the plate drill 16 and 17. The plate positioning bar
23 has a plurality of pin holes 27 along its length
in to which pins are positioned in a conventional
manner to affix photographic negatives and plate
material so that they can be dri:Lled.
In the illustrated example, a spacer means 29
such as of pre-selected lengths of blocks having a
width to fit within the track ll and with edges
resting upon -the rails 13 and 14, spaces the drill 16
and 17 apart. The length of each o the blocks of
the spacer means 29 is selected to accord with a
particular size of plate cylinder. As there are many
different si~es oE plate cylinders, a selection of
difEerent lengths of spacer means 29 i8 preferclbly
maintained to quickly set the spacing between the
plate drills 16 and 17.
The registration table 2, Figs. 4, 5 and 6 is
designed to mount the imaged ~nd processed flexible
printing plate to a plate cylinder 33 located
adjacent the registration table 2, Fig. 4. In the
illustrated example, the registration table 2 is
formed of a table supported on front and rear sets of
legs 35 and 36 with an upper, planar work surface 37
supported thereby. Preferably, at least the front
legs 35 are adjustable in height to vary the tilt of
the work surface 37 for ease of working thereon and
transferring the plate to the plate cylinder 33.
Tilt of the work surface 37 is ~ontrolled b~
extension of the front legs 35 through a tube lock
38. A guide rod 40 i5 mounted to the work surface 37
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1 adjacent and outward of the table front edge 41 and
has rollers 42 rotatable and slideably mounted on the
guide rod 40 for lateral movement along the rod 40 to
accommodate di~ferent size plate cylinders 33 and
bear against the surface of the cylinder.
A plate mounting bar 44 extends across the work
surace 37 and, in the i]lustrated example, is
slideably affixed thereto by slicle means including
opposite rails 45 and 46 mounted to the opposite side
edges 47 and 48 of the work surface 37. The s.ide
rails 45 and 46 position the plate mounting bar 44
parallel to the guide rod 40 for sweeping the plate
mounting bar 44 across the work surface 37 parallel
to the guide rod 40. The plate mounting bar 44
contains an array of pin holes 50 for inserting pins
51 in the bar pin holes 50 and pinning the printing
plate thereto.
The plate cylinder 33, to which the printing
plate 53 is to be affixed, is supported by its
spindles 54 in a cradle 55 and positioned so that the
plate cylinaer 33 is in even contact with the rollers
42 on the guide rod 40. In this position, the
~ longitudinal axis of plate cylinder 33 i9 parallel to
; the plate mounting bar 44.
In use, the printing plate 53, pre-drilled by
the drilling apparatus 1 and with the drill bores
aligned with the image thereon through conventional
means, is p.rocessed, and after processing i9 brought
to the registration table 2. Pins 51 are used to
attach the printing plate 53 to the plate mounting
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1 bar 44 and the plate mounting bar 44 holds the plate
53 in place and in registration parall.el with the
longitudinal axis of the plate cylinder 33 while the
printing plate 53 is applied to the cylinder 33. To
mount the printing plate ~3, the plate cylinder 33 is
covered with a double sided, sticky backed tape 56 in
the area of contact between the surface of the
cylinder 33 and the plate 53 and the rolle~s
positioned so that they ride against the surace of
the cylinder 33 and not in contact with the sticky
backed tape 56. The plate mounting bar 44, with the
printing plate 53 attached, is drawn toward the table
front edge 41 and the overhanging lip of tlle printing
plate 53 adhered to the plate cylinder 33. The plate
cylinder 33 is gradually rotated, applying more and
more of ths printing plate 53 to the cylinder surface
until no more of plate can be withdrawn because of
the plate being pinned to the plate mounting bar 44.
Thereupon, -the pins 51 are removed and the plate 53
will be sufficiently secured to the cylinder 33 so
that the remainder of the plate 53 can be rolled on
to the cylinder without shifting of the plate 53.
By this procedure, orientation of the work to
the longitudinal axis of the plate cylinder need only
be done once, at the drilling apparatus 1, and ~rom
that point onward, registration of the printing plate
: 53 with the plate cylinder 33 is as easy as merely
pinning the plate to the plate mounting bar 44 and
then rolling the plate on to the plate cylinder 33.
This procedure saves many hours of work and results
11
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1 in detailed registration of the selected longitudinal
axis oE the image with the longitudinal axis of the
plate cylinder 33.
It is to be understood that while one form of
this invention has been illustra~ed and described, it
is not to be limited to the speci.fic form or arrange-
; ment of parts herein described and shown, except
insofar as such limitations are i.ncluded in the
following claims.
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