Note: Descriptions are shown in the official language in which they were submitted.
Background oE the Invention
. ~
The inven-tion is useful in the printiny of a
con-tinuous web composed of any suitable material, e.g. paper,
plastic, or metal. An important application of the invention
is in the multi-color flexographic printing of packaging
material. It is a known disadvantage to use flexographic
printing of a continuous web of packaging material, when the
printing pattern on the plate cylinder contains large blank
areas which produce considerable waste of the web between the
repetitive patterns of printed matter. Another disadvantage
of using a conventional, flexographic printing press is that
the plate cylinder must be changed to accommodate different
size printing patterns and printed messages. Further, it is
necessary to adjust the positions of the plate cylinder and
the transfer and fountain rollers to adapt the press to plate
cylinders of varying diameters. The invention is directed to
the provision of a flexographic-type printing press with none
of the aEorementioned disadvantages.
Briefly stated, the invention is a flexographic
belt printing press including an endless belt extending around
plate and idler rolls and having printing plates on the
outer surface thereof, the idler roll being movable toward
and away from the plate roll for adjusting the belt tension
and for accommodating belts of different size, impression and
inking rolls mounted for pivotal movement toward and away from
the plate roll into and out of engagement with the printing
plates, selectively operable fluid cylinders for so moving
the impression and inking rolls, and selectively adjustable
stops for precisely locating the impression and inking rolls
when they are pivoted toward the impression roll so that they
engage the plates with predetermined pressure for optimum
printing performance, whereby removal of the belt and
replacement of same is simplified by selectively operating
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the ~luid cy:linders ~or pivoting the impression and inkiny
rolls away from the p]ate roll, and relocation of the
lmpression and inking rolls in en~agemen-t with plates on a
new belt with substantially the same predetermined force for
repeatable optimum printing performance by a new belt with
little or no readjustment is achieved simply by operating the
fluid cylinders for pivoting the impression and inking rolls
toward the plate roll into engagement with the stops.
~ feature of a belt-type printing press is tha-t
the size and location of the plate cy~inder, transfer and
fountain rollers need not be changed when the length of the
printing pattern is changed. It is only necessary to change
the belt to produce different printing patterns or the size
of the printed matter on the continuous webO
Description of the Drawings
-
The following description of the invention will
be better understood by having reference to the accompanying
drawings, wherein-
Fig. 1 is a plan view of a belt-type printing press
employing the invention as seen from -the line 1-1 of Fig. 2,
Fig. 2 is a side elevation of the press, as
viewed from the line 2-2 of Fig. l;
Fig. 3 is a side elevation of the press, as viewed
from the line 3-3 of FigO l; and
FigO ~ is an end elevation of the press~ as
viewed from the line 4-4 of Fig. 2.
De ~
With reference to the drawing, there is shown a
belt-type printing press 5 which is designed for printing on
a continuous web ~ of any suitable material such as paper~
plastic, or metal~ The printing press 5 comprises an impression
cylinder assembly 7 which is in juxtaposed relation vertically
above a plate ~ylinder assembly 8 when the press 5 is in a
normal vertical position and rests on a horizon-tal surface
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Impression Cylinder Assembly
The impression cylinder assembly 7 comprises an impression
cylinder 9 which is rotatable about its longitudinal axis that
is normal to the dlrection in which the continuous web 6 travels
as it moves to and from the impression cylinder 9. The impression
cylinder 9 is rotatably mounted between a pair of parallel
pivot arms 10,11, each of which have a pair of opposi~g ends
12,13. The pivot arms 10,11 are mounted on the upper framework
14 of the printing press 5 for unitary rotation about an axis
which is parallel to the rotational axis of the impression
cylinder 9 and located intermediate the opposing ends 12,13 of
the pivot arms 10,11.
A pair of air cylinders 15,16, designed to function, in
unison, are operatively connected between the upper framework
14 of the printing press 5 and adjacent ends 13 of the pivot
arms 10,11, to rotate the impression cylinder 9 about the
rotational axis of the pivot arms 10,11, between operating and
non-operating positions, i.e. into and out of printing relation
with the plate cylinder assembly 8. The free ends 12 of the
pivot arms 10,11 each carry a plurality of adjustable stops
17-19 which are strategically located for engaging a set of cor-
respondingly positioned abutments or stops 17'-19' adjacent each
of the free ends 1~ of the pivot arms 10,11 to control the
positioning of the impression cylinder 9. The vertically upper-
most set of stops 17,17' are used in the positioning of the
impression cylinder 9 in its vertically lowermost operating
position relative to the plate cylinder assembly 8. The first
to encounter vertically lowermost set of stops 18,18' are designed
to regulate the normal non-operating position of the impression
cylinder 9, out of printi.ng engagement with the plate cylinder
assembly 8. The second to encounter lowermost set of stops 19-19'
are used to regulate the fully retracted position of the
impresslon cylinder 9 away from the plate cylinder assembly 8, to
permit the continuous web 6 to be more conveniently threaded
through the impression cylinder assembly 7. Similar conventional
air cylinders 20 are provided to reposition the first to encounter
set of stops 18,18' to permit engagement of the second to
encounter set of stops 19,19'.
A hand operated wheel 21, in conjunction with a pair of
digital readout devices 22,23 correlated to the turning of the
wheel 21 is provided to help an operator locate the set of
operating stops 17,17' to properly position the impression
cylinder 9 for printing relation with the plate cylinder assembly
8.
A compensator roller mechanism 24 is used to adjust the
length of the pathway which the continuous web 6 travels between
a pai.r of similar adjacent printing presses 5 normally employed
in a multi-color printing operation to control the registration
of color to color. The mechanism 24 comprises a spring biased
compensator roller 25 whose vertical position is automatically
controlled by operation of a motor, or manually adjusted by a
hand operated wheel 26 in conjunction with a pair of digital
readout devices 27,28, similar to that used in adjusting the
position of the operating stops 17. The spring biased compensator
roller 25 is designed to rotate freely about its longitudinal
axis which is parallel to the rotational axis of the impression
cylinder 9. Any other suitable means can be used, to bring about
registration of color to color, if desired.
Plate Cylinder Assembly
The plate cylinder assembly 8 comprises a plate cylinder 30
which is rotatable about its longitudinal axis that is parallel
to the rotational axis o-E the impression cylinder 9. A continuous
flexible belt 31 is at least partially reeved around the plate
cylinder 30 and carries a plurality of printing plates similar to
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those used in a conventional flexographic printing process. The
printing plates are bonded in position on the flexible belt 31
which is composed of any suitable material, as is well known in
the trade. The belt 31 is also reeved at least partially around
a smaller roller 32 which is provided to tension the belt 31
on the plate cylinder 30. The belt tensioning roller 32 is
mounted for rotating freely about its longitudinal axis which is
parallel to the rotational axis of the plate cylinder 30. Any
suitable mechanism 33 may be used to adjust the position of the
belt tensioning roller 32 relative to the plate cylinder 30, to
accommodate belts of different lengths used in the multi-color
printing process.
For example, the mechanism 33, as best seen in ~ig. 4,
comprises a pair of vertically disposed parallel drive screws
34,35 which are operatively connected to any suitable drive
mechanism 36 for rotating the drive screws 34,35, in unison.
A pair of parallel guide rods 37,38 are disposed in parallel rela-
tion within the drive screws 34,35, and a pair oE carriages
39,40, are slidably mounted on the guide rods 37,38, and coupled
to the drive screws 34,35 which, when rotated, cause the
carriages 39,40 to move along the guide rods 37,38. The belt
tensioning roller 32 is rotatably mounted between the carriages
39,40. The pair of drive screws 34,35 are allowed to float,
i.e. they are mounted for limited axial movement relative to
the adjacent guide rods 37,38 which are fixedly mounted on the
lower framework 41 of the printing press 5.
A pair of simllar, double acting air cylinders 42,43 are
coupled by any suitable means 44 to the drive screws 34,35 and
carriages 39,40 to counterbalance the weight of the belt ten-
sioning roller 32 and to place a desired, downwardly directedforce or load on the carriages 39,40 to correspond:ingly move
the belt tensioning roller 32 to a position where the belt 31
is placed under a predetermined tension on the plate cylinder 30
for printing engagement with the continuous web 6 passing between
the nip of the impression cy~inder 9 and plate cylinder 30.
A conventional, engraved ink transfer roller 45 and founiain
roiler 46, as best seen in ~igs. 2 and 3, are associated with
the plate cylinder 30 and employed to transfer ink 47 from a
fountain 48 to the printing plates carried by the belt 31. Any
suitable mechanism such as a.n air loaded doctor or scraper blade
SB can be used, if desired, to remove excess printing ink from
the transfer roller 45. The scraper blade SB can be mounted in
a positive angle position, as shown in ~ig. 2, or a reverse
angle position as shown in Fig. 3. The fountain 48 i5 mounted by
any appropriate means for movement to and from the fountain
roller 46. The transfer roller 45 and fountain roller 46 are,
like the belt tensioning roller 32, mounted for rotation about
their own particular longitudinal axes which are parallel to the
rotational axis of the plate cylinder 30. The transfer roller 45
is rotatably mounted between adjacent ends 49,50 of a pair of
parallel arms 51,52 which are provided to support both the
transfer roller 45 and the fountain roller 46 on the plate
cylinder assembly 8. The support arms 51,52 are mounted for
rotation about an axis 53 which is parallel to the rotational
axis of the plate cylinder 30 and which is located intermediate
the rotational axis of the transfer roller 45 and opposing free
ends 54,55 of the support arms 51,52. A pair of air cylinders
56,57 are coupled between the lower framework 41 of the printing
press 5 and the adjacent free ends 54,55 of the support arms
51,52 to rotate the support arms 51,52 and move the transfer
roller 45, carried thereby, to and from the plate cylinder 3Q.
The fountain roller 46 is rotatably mounted between a pair
of parallel pivot arms 58,59 intermediate opposing ends 60,61 and
62,63 thereof. The ends 60,61 of the pivot arms 58,5g, closest
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the transfer roller 45, are pivotally mounted by similar pivot
pins 64 to a pair of brackets 65,66 which project from the sup-
port arms 51,52 in parallel relation adjacent the transfer roller
45. A pair of air cylinders 67,68 are coupled between the
opposing free ends 62,63 of the pivot arms 58,59 and the adjacent
free ends 54,55 of the support arms 51,52 to rotate the fountain
roller ~6 to and from the transfer roller 45. Thus, the transfer
roller 45 and fountain roller 46 are mounted for relative
rotational movement to and from each other and for unitary
rotational movement to and from the plate cylinder 30.
A plurality of sets of stops 70,71 and 72,73 and 74,75
similar to those used in conjunction with the support arms 10,11
of the impression cylinder 9, are provided for coaction with the
free ends 54,55 of the support arms 51,52 of the transfer roller
45, to position the transfer roller 45 for engagement with, and
disengagement from, the printing plates carried by the belt 31
and passing around the plate cylinder 30. The first set of stops
70,71, closest the free ends 54,55 of the support arms 51,52, are
utilized to posi-tion the transfer roller 45 adjacent the plate
cylinder 30 for transferring ink to the printing plates carried
by the belt 31. The second set of stops 72,73 are used to
regulate the normal position of the transfer roller 45 out of
engagement with the printing plate carried by the flexible belt
31. Conventlonal air cylinders 76 are also provided to retract
the stops 73 of -the second set of stops 72,73 out of inter-
ference wlth the coaction of t'ne third set of stops 74,75, at
which point the transfer roller 45 is in farthest spaced relatlon
from the plate cylinder 30. A hand operated wheel 77 and
digital readout devices 78,79 are likewise employed to position
the first set of stops 70,71 for controlling the ink transferrlng
position of the transfer roller 45 relative to the plate cylinder
30.
The plate cylinder 30 and transfer roller 45, as best seen
in Figs. l and 3, are conventionally geared together for
synchronized rotation relative to the linear speed at which the
web 6 travels between the nip of the impression and plate
cylinders 9,30 and are operated by any appropriate drive
mechanism which is coupled to the projecting end 80 of a power
input shaft 81 that is geared to the plate cylinder 30 and trans-
fer roller 45. The fountain roller 46 is operated or rotated
independently of the transfer roller 45 by any suitable motor
means M and at a speed and distance from the transfer roller 45
sufficient to meter a lmiform and constant desired flow of ink to
the printing plates carried by the belt.
A motor driven or hand operated wheel. 82 and locking
mechanism 83 are provided for use by an operator in axially ad-
justing the position of the plate cylinder 30 relative to the
impression cylinder 9.
Thus, there has been described a novel, compact printing
press which is especially suitable for use in the multi-color
printing of a continuous web of any appropriate packaging
material. A number of these compact printing presses are dis-
posed one after the other to successively print upon the moving
web, different colors used in the multi-color printing process.
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