Flexographic ink distribution system

A system for applying and then removing ink in a metering fashion from a roll. A wire wound rod is rotated in a direction opposite of an ink applicator roll with the rod and roll in contact together. Ink is applied uniformly across the outer surface of the applicator roll with a portion of the ink then being removed from the applicator roll by the wire wound rod. The ink remaining on the applicator roll is then transferred to a printing plate provided on a roll rotatably mounted adjacent to the applicator roll. Spring biased washer seals mounted to the metering rod engage the opposite ends of the applicator roll and the metering rod mounting block limiting ink flow therefrom. Ink drainage channels in the metering rod mounting block drain the ink therefrom into a receptacle connected by conduits to a reservoir and pump operable to direct ink back onto the roll. An inflatable pressurized container is operable to move the metering rod to and from the applicator roll.

BACKGROUND OF THE INVENTION 
This invention is in the field of printing and more specifically systems 
for applying ink to an applicator roll in a metering fashion. In 
flexographic printing, the board to be printed is passed between a 
rotating plate cylinder and an impression roll. The plate cylinder has 
mounted thereon a printing plate contactable with a third roller applying 
ink to the plate once per revolution of the plate cylinder. Fresh ink is 
continuously applied to the applicator roll with some type of device used 
to remove excess ink from the outer surface. 
The prior applicator rolls are metal with a finely engraved outer surface 
provided to hold the ink upon the surface of the roll. The printing plate 
contacting the applicator roll is produced from rubber or photopolymer 
material resulting in a rapid deterioration of the printing surface. 
Eventually, the applicator roll which is very large and heavy must be 
removed from the printer and shipped back to a repair facility. The 
removal of the roll requires complete shutdown of the printer for several 
days. Once the applicator roll arrives at the repair facility, it is 
machined down, in certain cases recoated with metal and then engraved. The 
engraved surface may be as coarse as seven cells per lineal inch or a fine 
as five hundred cells per lineal inch. The cell is either in an inverted 
pyramid shape configuration with an outer square opening and a pointed 
base or as a quad cell configuration having an outer square opening but a 
reduced square base and slightly inclined walls. In either event reworking 
of the applicator roll is quite expensive and requires a large amount of 
time to repair and reinstall in the printer. 
It is the practice to remove the ink from the engraved applicator roll once 
contacted by the printing plate by either a rubber wiper roll contacting 
the applicator roll or an air activated doctoring or meter blade. An 
expandable air tube or a series of air cylinders mounted adjacent the 
blade moves the blade to and from the applicator roll to remove the excess 
ink from the roll. The use of the rubber wiper roll with a cellular 
applicator roll provides an alternative method for removing excess ink 
from the surface of the applicator roll. Further, as the engraved 
applicator roll is used ink buildup along with dirt will accumulate on the 
roll requiring frequent cleaning of the applicator roll. Another 
disadvantage of the cellular applicator roll is the requirement of even 
ink distribution across the applicator roll to prevent the roll from 
burning during operation. 
Disclosed herein is a printer having a rubber applicator roll with a smooth 
outer surface. A rod having a wire wound or similarly contoured surface is 
used in conjunction with a device applying ink to the applicator roll for 
the purpose of finely metering and removing excess ink from the applicator 
roll prior to ink transfer to the printing plate. The wire wound rod is 
small and lightweight allowing for very simple and quick removal from the 
printer for the purpose of installation of a new rod having a different 
metering capability depending upon the size of the wire wrapped thereon. 
The rubber applicator roll does not wear nearly as fast as the metallic 
cellular applicator roll. The necessity for refinishing of the applicator 
roll as previously described is completely eliminated. Superior printing 
results are achieved since the ink may be metered on the applicator roll 
through the use of different wire wound rods depending upon the type of 
printing required. For example, heavy or large lettering requires a large 
amount of ink on the applicator roll and thus a metering rod having a 
large wire wrapped thereon is utilized as compared to fine small printing 
in which case a metering rod having a fine wire wrapped thereon is 
utilized. Previously, the metallic cellular applicator roll having a fixed 
configuration was used for all printing including fine and large printing 
due to the large amount of time and effort required for the removal of the 
applicator roll. Thus the prior applicator rolls would be chosen to apply 
an average amount of ink somewhere between what was actually required for 
fine printing and heavy printing. The results using such an applicator 
roll are unsatisfactory. 
The metering rod and rubber roll system disclosed herein are designed to be 
included as original equipment or installed into existing printers in the 
form of a kit. The cost of such a system is significantly lower as 
compared to the cellular applicator roll. 
Grooved rollers have previously been used for a variety of tasks. For 
example, U.S. Pat. No. 3,718,117, issued to Lewicki, Jr. discloses a 
grooved rod used to apply a uniform coating of particulate containing 
material. A similar device is disclosed in U.S. Pat. No. 3,312,191, issued 
to Lowe. Likewise, a grooved roller for use in a rotary printing press is 
disclosed in U.S. Pat. No. 3,098,437, issued to Tyma, Jr., et al. whereas 
U.S. Pat. No. 3,613,575, issued to Kantor discloses a grooved oscillator 
roll for use in a printing press to achieve break up and distribution of 
the substances with which it comes into contact. 
SUMMARY OF THE INVENTION 
One embodiment of the present invention is a system for applying and then 
removing in metering fashion ink from a roll comprising first means 
including ink and having an outlet adjacent the roll operable to apply ink 
to the roll; and second means operable to meter and remove excess ink from 
the roll and including a member with an outer surface with parallel ridges 
thereon separated by grooves to receive ink from the roll as the ridges 
contact the roll and meter ink therefrom. 
Another embodiment of the present invention is a device for removing a 
liquid like substance from a roll comprising a rod mounted adjacent the 
roll and extending the length thereof, the rod including a grooved outer 
surface with ridges thereon in contact with the roll, said grooves are 
separated by the ridges and are arranged to limit flow of the substance in 
one groove to another groove at the location of contact with the roll. 
It is an object of the present invention to replace the engraved and random 
cell ink transfer roller utilized in flexographic printers with a soft 
resilient roller. 
A further object of the present invention is to transfer ink to a printing 
plate from a soft resilient roller. 
Yet another object of the present invention is to meter ink from a soft 
resilient roller by means of a metering system leaving only the correct 
amount of ink on the transfer roller and depending upon the type of 
printing to be accomplished.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
For the purposes of promoting an understanding of the principles of the 
invention, reference will now be made to the embodiment illustrated in the 
drawings and specific language will be used to describe the same. It will 
nevertheless be understood that no limitation of the scope of the 
invention is thereby intended, such alterations and further modifications 
in the illustrated device, and such further applications of the principles 
of the invention as illustrated therein being contemplated as would 
normally occur to one skilled in the art to which the invention relates. 
Referring now more particularly to FIG. 1, there is shown a printer 10 
having a cylindrical impression roll 11 rotatably mounted on axle 12 to 
move in the direction of arrow 13. Printer 10 further includes a plate 
cylinder 14 rotatably mounted on axle 15 to move in the direction of arrow 
16 and having mounted thereon a printing plate 17 with the required 
indicia to print upon board 18. Plate 17 is spaced apart from the outer 
surface of impression roller 11 a sufficient distance to allow board 18 to 
pass in the direction of arrow 19 between the cylinder and roll while 
being impressed thereon the indicia upon plate 17. 
A resilient applicator roll 20 is rotatably mounted to axle 21 and is 
rotated in the direction of arrow 22 past the ink distribution system 23 
applying and metering ink upon roll 20 prior to the roll contacting plate 
17. Plate 17 is spaced a sufficient distance from applicator roll 20 to 
contact the applicator roll once per revolution of plate cylinder 14. 
Ink distribution system 23 (FIG. 2) includes first means 24 for applying 
ink to applicator roll 20. The first means 24 has a main body 25 with a 
hollow interior in communication via a main ink inlet 26 with a reservoir 
27 of ink. A conventional pump 28 is disposed between and connected by 
conduits 29 and 30 to the reservoir 27 and main ink inlet 26. The ink 
flows through inlet 26 into main body 25 and exits the main body by a main 
ink outlet 31 and a plurality of downwardly extending outlets 32 opening 
over and adjacent roll 20. The outlets 32 are spaced along the length of 
roll 20 to achieve an even distribution of the ink on the applicator roll. 
Block 40 is fixedly mounted to the frame supporting the three rolls with a 
second block 41 hingedly mounted to block 40 by means of a conventional 
hinge or fastener 42. Metering rod 43 is rotatably mounted to block 41 
being received within a semi-circular channel 44 (FIG. 5). End 45 of rod 
43 is bearingly received and mounted by bearing block 46 with the opposite 
end of rod 43 having a hexagonally shaped configuration and being 
removably received by socket 47 of block 48 in turn fixedly secured to a 
conventional gear 58 mounted to bearing block 49 by axle 50. Gear 58 is in 
meshing engagement with gear 51 rotatably driven by conventional motor 52. 
Suitable means is provided for the mounting of block 48 to facilitate the 
removal of rod 43, such as, spring biasing block 48 and axle 50 in 
position. A pair of dish shaped washers 53 and 54 are mounted to rod 43 
and are urged against the opposite ends of block 41 and applicator roll 20 
to prevent or to limit the flow of ink outwardly from the opposite ends of 
block 41. A pair of helical springs 55 are mounted to rod 43 and urge 
seals 53 and 54 against the opposite ends of the applicator roll. 
A fragmentary perspective view of the metering rod 43 is shown in FIG. 7. 
Metering rod 43 has a main cylindrical body 60 with a wire 61 helically 
wound along the length of main body 60 forming a plurality of ridges 62 
between which are located grooves 64. Each wire has a cylindrical 
cross-section providing a curved outer surface for contacting the rubber 
applicator roll. Such a wire wound metering rod may be purchased from RK 
Print-Coat Instruments Ltd., Southview Laboratories, Litlington, Royceton 
Hoyston, Herts. The rods sold by RK Print-Coat Instruments Ltd. are for 
the purpose of manually applying all types of materials including inks to 
a surface for testing under very exact conditions. The rod has heretofore 
not been used in a printer for metering ink on an applicator roll. The 
wire wrapped on the metering rod is available in diameters from 0.002 to 
0.060 inches. The outsdie diameter of the metering rod is less than 
one-half inch and is therefore less than one-tenth of the outside diameter 
of the applicator roll. A single wire is helically wound on the metering 
rod; however, the same results will be obtained by winding multiple wires 
in side by side fashion on the rod. The grooves between the adjacent coils 
of the wire provide a channel for metering away the unwanted ink upon the 
applicator roll. As such, the wire coils are arranged to limit flow of ink 
from one groove to another groove at the location of contact with the 
applicator roll. Best results have been obtained in rotating the metering 
rod in a direction opposite the direction of rotation of roll 20. One of 
the washer seals shown in FIG. 1 is fragmented to clearly illustrate the 
metering rod contacting the outer surface of the rotating applicator roll 
20. 
A plurality of cut out portions or reliefs 70 are provided in mounting 
block 41 and are positioned along the lengths thereof corresponding to the 
locations of the downwardly extending outlets 32. Thus, as metering rod 43 
contacts the applicator roll the excess ink on the roll will be metered or 
taken from the roll flowing through the grooves 64 (FIG. 6) of the 
metering rod and into reliefs 70 in turn leading to a plurality of 
downwardly extending channels 71 emptying into a receptacle 72 (FIG. 2). 
Receptacle 72 has a hollow interior with a downwardly sloping bottom wall 
l73. The wall slopes downwardly as viewed in FIG. 2 from right to left. A 
conduit 74 is connected to the main ink outlet 71 of ink dispenser 24 with 
the opposite end of conduit 74 connected to receptacle 73 allowing ink to 
be flushed through the receptacle for cleaning purposes. A second conduit 
75 leads from the outlet of receptacle 73 back to reservoir 27 with pump 
28 providing sufficient force to circulate the ink. The ink then passes 
onto the metering rod and through the receptacle back to reservoir 27. 
A conventional expandable pressurized container or air bag 76 (FIG. 5) is 
mounted within cavity 77 of block 40 and is connected to a source of 
pressure 78. Source 78 applies pressure to container 76 forcing the 
container to expand and causing block 41 and metering rod 43 to pivot with 
rod 43 contacting the applicator roll. Release of pressure by the source 
allows deflation of the pressurized container allowing the metering rod to 
swing back from the applicator roll. In the event that a large amount of 
ink is to be removed from the applicator roll, then a metering rod with a 
relatively small diametered wire wound on the metering rod is utilized 
whereas if a small amount of ink is to be removed from the applicator roll 
then a metering rod is utilized having a relatively large diametered wire 
wound thereon. 
Many variations are contemplated and included in the present invention. 
Best results have been obtained by rotating the metering rod at 
approximately thirty revolutions per minute; however other speeds are 
satisfactory. Further, the applicator roll should be produced from a 
non-metallic elastic material such as rubber or suitable plastic. The 
metering rod may be utilized in devices other than printers such as for 
metering adhesives on a roll. An additional roller running parallel to and 
in contact with applicator roll 20 may be employed when necessary to 
smooth out the ink on the applicator roll and eliminate any undesirable 
accumulations of ink on the applicator roll. 
FIGS. 8 and 9 show an alternate embodiment of the present invention 
identical to that previously described except the rotating metering rod is 
replaced with a stationary metering plate and the ink flow removal 
channels in the holder are different in configuration. Thus, holder 80 is 
hingedly mounted to block 81 and is movable to and from the applicator 
roll 20 by means of air bag 76 connected to a source of pressure 78. A 
pair of dish shaped washers or seals 53 and 54 are mounted by headed rods 
82 and 83 secured to block 80 and urged against the opposite ends of block 
80 and roll 20 by springs 84 and 85. 
A plate 86 is bolted to the bottom of block 80 and forms a V-shaped ink 
reservoir 87 with block 80. The top edge 88 and bottom edge 89 of plate 86 
are provided with a plurality of parallel ridges separated by grooves 
extending in the direction of rotation of roll 20 shown by arrow 90. As 
roll 20 rotates past the ink supply 91, ink is deposited atop roll 20 with 
roll 20 then rotating past and in contact with the top edge 88 of plate 86 
which removes in metering fashion excess ink from the roll prior to the 
roll contacting the printing plate or an adjacent roll. The ink removed by 
plate 86 accumulates in the V-shaped reservoir 87 and then flows out 
passages 92 to receptacle 72 (FIG. 2) and recirculates to supply 91. 
Passages 92 are located approximately 1/32 inches above top edge 88 shown 
by dimension 93 allowing the ink to flow evenly across roll 20 at the 
location of contact with top edge 88. The grooves and ridges on bottom 
edge 89 are of different size than those on top edge 88 allowing for 
reversal of the plate facilitating different metering of the ink from roll 
20. 
While the invention has been illustrated and described in detail in the 
drawings and foregoing description, the same is to be considered as 
illustrative and not restrictive in character, it being understood that 
only the preferred embodiment has been shown and described and that all 
changes and modifications that come within the spirit of the invention are 
desired to be protected.