Note: Descriptions are shown in the official language in which they were submitted.
1~(163~
This invention relates to offset litho-
graphic printing presses and particularly to an
improved planetary inker incorporating only one ink
form roller for sîmplification of the system produc-
ing economies insofar as fabrication is concerned as
well as maintenance and cleanup, without sacrifice
in printing quality over multiple ink form roller
trains.
In lithographic printing operations, ink
from a fountain supply thereof is delivered to the
ink receptive plate on the plate cylinder of the press
through a series of rollers which must furnish an
adequate volume of ink as used while avoiding over
supply, particularly to those areas of the plate
which require no ink or significantly less amounts
than adjacent printing areas of the plate. In most
instances, ink is removed from an ink ball rotating
in the fountain through use of a ductor roller that
alternates between a position contacting the ink ball
to a location in rolling contact wi.-th a vibrator
roller which transfers ink to a roller train. Con-
ventionally this includes at least two oscillating
vibrator rollers and a number of ink rider rollers
which mill the ink transferred to them by the ductor
system. Ink must be transformed from the thick surge
of ink transmitted from the ink fountain into a thin
uniform film of ink. The inking system must have a
large enough storage capacity to prevent a visible
drain on the amount of ink transmitted to the plate
during the time the ink ductor is against the ink
fountain. Ideally, there should be no visible differ-
ence in the amount of ink transferred to the plate
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~ 3~)63~3
at any time. Another func-~ion of the ink system is
to replenish the ink to the form rollers which the
plate cylinder removes from them by the time that
the form rollers make one revolution and come in con-
tact with the plate a secorld time. If ink is not
fully replenished, poor quality printing will result.
This printing will have àreas which are lighter than
others due to lack of sufficient ink on the form
roller in those areas. This phenomenon is referred
to as "ghosting". Ghosting is a serious problem on
printing which requires large areas of heavy ink
coverage in combination with large areas of little or
no ink coverage. In order to overcome the problems
of ink surge and ghosting which are diametrically
opposite from each other insofar as cause and effect
are concerned, it has normally been the practice to
provide two, three or four form rollers in rolling
contact with ~he plate cylinder to assure that a
proper amount of ink is transferred to the plate with-
out excessive delivery thereof.
In most inkers now in use, the roller train
is oriented so that the individual rollers are posi-
tioned to receive ink from a roller higher in the
train and operable to apply ink to a roller lower in
the ink train. As ink is transferred from one roller
to the next, the ink is smoothed out into a semi-
uniform film of ink. For increased s-torage and better
milling action, rider rollers are sometimes added to
the ink train. Generally, conventional ink trains
have three types of rollers. The first is so~t rubber
covered undriven rollers. These are generally referred
to as form rollers and function to transmit ink to the
" ~ "J, ~!, 3
- 1~3~)~38
plate cylinder. The secon~ type of roller is repre-
sented by undriven metallic rider rollers which are
used to transmit ink between two rubber rollers or
as a rider rollerlon a rubber roller. Oftentimes six
or more of these rider rollers are provided in a
typical ink train. The thlrd type of roller is the
driven metallic roller which usually takes the form
of a vibrator or distributor roll which oscillates
along its axis during rotation to drive the undriven
rollers, mill the ink, and distribute the ink from
side to side. Generally speaking~ the axial stroke
of vibrator rollers is of the order of one-half to
one inch.
An ink form roller i-n rolling contact with
the plate of a printing press receives ink from the
vibrator roller thereabove and applies such ink to
the plate cylinder. It is assumed that when two rollers
are in rolling contact the total amount of ink at the
line of contact therebetween is divided equally
between the two rollers. In non-printed areas of
the printing plate, no ink is transmitted from the
form roller -to the plate. Therefore, immediately after
leaving the plate, the form roller has areas which have
twice as mueh ink as other areas where ink was picked
up by the ink receptive areas of the plate. As the
form roller continues to rotate, it comes in contact
again with the vibrator roller. All areas of the
form roller receive ink from the vibrator but the ,
areas of the form roller with the most ink originally
present thereon will have a greater amount of ink
after leaving the vibrator. Since the form roller
is generally of substantially less diameter than the
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638
plate cylinder and thereby has less total surface '~
area, the portions of the form roller from which ink
was removed by the plate and thereby having the least
amount of ink will be out of phase with the area of
the plate it contacted on the previous revolution.
This can result in an inconsistent amount of ink being
transferred to the plate which will cause light and
dark "ghosted" areas in the printing.
To overcome this problem, conventional inkers
have a series of ink form rollers (two to four) around
the plate cylinder. Sometimes, ink form rollers of
different sizes will be used so that the ghosted
areas of the form rollers will be out of phase with
respect to each other. Ink will thus be deposited
in the ghosted areas of the plate from the first form
roller by the second form roller. Ink will next be
deposited in the ghosted areas of the plate from the
first and second form rollers by a third form roller,
if one is present. If the machine is equipped with
a fourth form roller, it will deposit in the ghosted
areas of the plate from the first, second and third
form rollers respectively.
Although utilization of a number of ink
form rollers on a plate accompanied by a large number
of distributor rollers in the ink train leading from
the ink fountain supply will solve most ghosting pro-
blems regardless of the copy being printed, the over~
all complexity of the ink train has been significant-
ly increased and maintenance and cleanup oE the equip- ~
ment consumes more time and is therefore more costly F
to ~he operator, par~icularly where diEEerent types 3
of jobs are sequentially run on a particular machine.
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~3~:1638
It is~ therefore, a primary object of the
present invention to provide an ink train for litho
graphic offset printing presses embodying a planetary
inker using only a single~ relatively large ink form
roller in rolling contact with the plate of the plate
cylinder, but which avoids ghosting problems without
excessive supply of ink by virtue of the utilization
of a unique combination of planetary oriented vibrator
and rider rollers operably associated with the single
ink form roller to smooth out the ink and effect even f
distribution thereof, no-twithstanding the intermittent
surge supply which is inherent in the ductor transfer
of ink from the fountain ink ball to the first vibrator
roller.
A further important object of the invention ~ .
is to provide a planetary inker as described which over- ;
comes many of the ink surge problems encountered with
conventional systems by the utilization of a pair of
ductors between the ink ball and the form roller
vibrator which alternately intermittently engage the
ink ball and vibrator respectively to thereby
permit more continuous supply of ink to -the train
at a required rate without regard to press speed or
layout of the copy to be printed. In this regard,
a further important object of the invention is to E
provide a double ductor ink supply for a planetary
inke-r wherein the relative time of engagement of
each ductor with the ink ball and with the vibrator
may be adjusted at will by the operator so that
delivery of ink to the ink form roller may be easily
and quickly adjusted as required with minimum paper
wastage. - r
.
3 8
Another very important object of the inven- -
tion is to provide a single ink form roller planetary
inker train for offset lithographic presses wherein
sufficient distributor rolLers are operably associated
3 with the form roller and of relative diameters with
respect to each other and to the form roller to assure
complete smoothing out of ink supplied to the form
roller in conjunction with total elimination of all
plate-derived latent images on the surface of the
form roller during rotation thereof.
Also, an object of the invention is to pro-
vide a planetary inker as described wherein at least
three planetary vibrator rollers are provided in
rolling contact with the form roller around the per-
iphery thereof and a series of rider rollers in con-
tact with at least two of the vibrator rollers to
smooth out the ink and remove all latent images
from the surface of the form roller before recontact
thereof with the plate on the pla~e cylinder. In
the embodiments illustrated, the single ink form roller
is of a diameter greater than that of the plate
cylinder, and at least seven and preferably from
eight to ten supply distributor rollers made up of
vibrator rollers and rider rollers are provided
around the form roller for even spreading and re-
supply of ink to the form roller as required. How-
ever, the form roller may be of any desired size rela-
tive to the plate cylinder provided it is of sufficient
diameter to accomodate an adequate number of distribu-
~r rollers around the periphery thereof. Since in
the most useful form of the invention, the rollers
of the distribu~ion train are not of the same size~
)638
the ghosted areas on the f:irst rollers in contact with
the form roller will be out of phase with the other
rollers, one complete revo:Lution of the form roller
causes the ink film thereon to again be very uniform
before coming into ink transferring relationship with
the plate of the plate cylinder.
U.S. Patent No. 3,298,305 shows a single
ink form roller in contact with the plate cylinder for
supplying ink to the plate thereof, with means being
provided to continuously deliver ink to the surface
of the form roller. However, no distributor rollers
are shown in association with the ink form roller and
ghosting problems could occur with a train of this
type unless extreme care was exercised in setting up
the machine and the unit used primarily for printing
relatively uniform copy insofar as ink demand is
concerned across the width of the sheet.
U.S. Patent No. 2,036,451 employs large
belts in contact with the plate cylinder and a multi-
plicity of rollers riding against the belt. However,
the belts are too flexible and the thickness thereof
cannot be adequately controlled. As a result, the
printed image formed would not be an accurate repre-
sentation of the original.
U.S. Patent No. 2,185,342 has rider rollers
in association with a form roller, but the patentee
suggests use of a doctor blade on the fountain roller
which would result in too much ink being supplied to
the system without effective means of regulating ink
delivery, particularly with respect to low demand
areas of the plate. Although a relatively large
number of rider rollers are employed by the patentee,
"~s, -8-
~3~3638
continuous feeding and doctoring of the ink makes it
impossible to clean up ~he rider rollers because of
excess supply of ink. Furthermore, ghosting would
still be a problem by virtue of the fact that the
i rider rollers are essentially all of the same effec-
tive diameter and no out o phase transfer of ink
to image areas wou].d be effected. A similar problem
exists with respect to the arrangement shown in U.S.
Patent No. 2,276,525, wherein a multiplicity of rollers
are supplied by a scraper blade controlled delivery
unit.
U.S. Patent No. 2,065,136 has a series of
rider rollers in association with form roller struc-
ture but the riders are inadequate in number to
effectively mill out the ink, remove plate-derived
latent images, and efEect even delivery to plates
having variable ink demand characteristics. Further-
more, the patentee's equipment is for planographic
as contrasted with lithographic printing and thus the
problems encountered cannot be related to those to be
solved in the offset press field. The same is true of
- the letter press apparatus shown and described in
U.S. Patent No. 1,865,184 wherein an inking form
roller comes in contact with the raised blocks that
have rider rollers in association therewith. Similarly,
U.S. Patent No. 3,585,932 is concerned with raised
image printing and also uses a doctoring ink control
technique.
In the planetary inker of this invention on
the other hand, one large soft rubber form roller is
mounted in rolling contact with the plate of the plate
cylinder. Arranged around this form roller are a
", ~ i". _ g _
~L3~638
series of supp]y and distributor rollers which include
a primary vibrator roller and two sets which each
include a hard metallic vibrator roller, at least two
rider rollers, one of which engages the form roller
while the other contacts the vibrator roller and the
associated rider roller, but not the form roller and
independent rider rollers between each of the cooper- ,
able sets of rollers. The purpose of the rider rollers 7
is to provide ink storage and effect milling of the
ink. The vibrator rollers serve to also mill the
ink, provide additional ink storage, and distribute
the ink from side to side~ These functions are very
similar to those which occur with the same types of
roller in a conventional inking system. It was to
be expected that with a single form roller in contact
with the plate, ghosting would occur as it often does
in ink trains heretofore in common usage. This was
not found to be the case, though. since the single
form roller has a sufficient number of rider rollers
and vibrator rollers around it which store ink and
resupply the form roller as needed. As a line on
the form roller rotates past the plate cylinder, it
will have light areas and dark areas as with conven-
tional inkers. As the line passes through the rider
roller and vibrator roller nips of a respective set
thereof, ink wil] be redeposited in those areas which
have less ink. This will be accomplished gradually
with each roller depositing a small amount of
additional ink. By virtue of the fact that the
various rollers of each independent set thereof are
not the same size, the ghosted areas on the flrst
rollers will be out of phase with the other rollers
t',
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6 3 ~ -
of the set. After the for~ roller makes one complete
revolution and has contacted all three sets of distri-
butor rollers, the plate-derived latent images on the
form roller are completely eliminated.
In the drawings:
~ Figure 1 is a side elevational, essentially
schematic representation oE a typical four color
perfecting offset printing press in which planetary
inker structure as described herein may advantageously
be used;
Figure 2 is a schematic showing of the roller
train of a perfecter planetary inker embodying the
preferred principals of the present invention and
useful in a press as shown in Figure l;
Figure 3 is also a schematic showing of the
planetary inker illustrated in Figure 2 and depict-
ing a preferred drive train for operating the driven
rollers of the ink supply assembly;
Figure 4 (on the sheet of Fig. 1) is a schematic showQng o~ a plane-
tary inker for offset presses which are operable to
print on only one side of a sheet of paper with
double ductor structure being employed for transferr-
ing ink from the fountain ink ball to the vibrator
roller running in contact with the ink form roller
of the system; and
Figure 5 (on the sheet of Fig. 1) is a sche~atic showing of a plane-
tary inker embodying the basic principals of the
invention but in this case employing only a single
ductor between the ink ball and the vibrator roller
running in contact with the ink form roller.
-11-
" ,,.,~,,
~ 3~638
In a conventional perfecting press such as
indicated generally by the numeral 10 in Figure 1,
a roll 12 of paper to be printed is rotatably suppor-t-
ed by roll stand 14 which includes web tensioning
mechanism so that as the sheet material is pulled
through the printing towers 16a to d inclusive,
accurate match between the different colored images
will be maintained for quality reproduction. The web
18 which exits from the last tower 16d and contains
printed images on both faces thereof passes through
dryer 20 and then chiller 22 before being directed ~r
to the next processing station. In many instances,
this consists of a folder 24 connected to a sheeter
delivery unit 26 that directs the sheets to stacker
28 which conventionally includes a jogger or the like. 5
A planetary inker 30 of preferred~construc-
tion for use in a perfecting printing tower such as
towers 16a to 16d inclusive is illustrated in the
Figure 2 of the drawings, with the upper and lower ink
roller trains being substantially identical except
for the specific orientation of the distributor
rollers with respect to the ~orm roller.
Considering first the upper ink train of
Figure 2, an ink receiving fountain 31 has an inclined
lower wall 32 which receives the viscous ink 34 to be
delivered to the plate 36 on plate cylinder 38. A
conventional ink ball 40 is rotatable relative to
inclined wall 32 of fountain 31 in a manner to pick
up ink from the supply thereof with such ink adhering
to the outer surface of the ball as a uniform coating
thereon determined by the stop positions of the foun-
tain control fingers.
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1~3~363~ ,
The upper planetary inker train 30a has a
single relatively large, rubber-covered ink form roller
42 in rolling engagement wi-th the plate 36 and of a
diameter somewhat greater than that of plate cylinder
38 whereby the form roller has a surface area which
exceeds that of the plate. ~ series oE supply and
distrib~ltor rollers made up o drum rollers and rider
rollers is operably associated with form roller 42 to
deliver ink thereto and smooth out the ink thereon
in a manner to eliminate all plate-derived latent
images before a re-inked area of the form roller
moves back into ink transfering relationship with the ¦
plate. Included in the series of supply and distri-
butor rollers made up of drum rollers and rider rollers
is operably associated with form roller 42 to deliver
ink thereto and smooth out the ink thereon in a
manner to eliminate all plate-derived latent images
before a re-inked area of the form roller moves back
in~o ink transfering relationship with the plate.
Included in the series of supply and distributor
rollers is a primary roller which for example may be
a drum roller such as vibrator roller 44 located
between the form roller and ink ball 40. In the pre-
ferred embodiment, a pair of mutually cooperable
rubber-covered ductor rollers 46 and 48 are mounted
for alternate, intermittent engagement between the
metal surface of ink ball 40 and metallic vibrator
roller 44. Ductors 46 and 48 are alternately shift-
able into engagement with ball 40 and then into roll-
ing contact wi-th vibrator roller 44. Pre~erably,
means is provided for allowing the operator to select-
ively adjust the time during which each ductor is in
13-
1~0638
engagement with the ink ball and also the time of
rolling contact with vibrator 44. In addition, best
results are obtained when one of the ductors is in
engagement with ink ball 40 while the other ductor
is in contact with vibrator 44. Ink transferred from
ball 40 to vibrator 44 is delivered directly to the
surface of form roller 42 as is evident from Figure 2.
Two sets of mutually cooperable distributor rollers
are associated with form roller 42 along with three
independently rotatable rider rollers between the
remaining distributor rollers of the system and also
the plate cylinder.
One of the distribution sets includes a
second drum or vibrator roller 50 making up a part of
the distribution system and positioned in rolling
engagement with the surface of form roller 42 is
spaced from vibrator 44 around the circumference of
the form roller and has an outer rider roller S2 in
engagement therewith, which also rolls against an
inner rider roller 54 spaced from vibrator roller ~O.
Independent rider roller 56 rides against the sur-
face of form roller 42 between rider roller 54 and
vibrator roller 54. The vibrator roller 50 as well as
the rider rollers described all are metal surfaced.
It is important to note at this juncture that the
rider rollers 52, 54 and 56 as well as vibra-tor
roller 50 all have diameters which vary and thus the
surface areas of the rollers are dif:Eerent. As will
be explained, this difEerence in surface area is im- '~
portant in elimination of latent images Erom the sur-
face of the form roller and also contributes to more
even spreading and smoothing of the ink across the
. ."~ .,, ~,
-14-
~1~L3~38
entire surface of the form roller before re-contact
thereof with the plate 36.
The second set oL distributor rollers includes
a drum or vibrator roller 58 in rolling engagement
with Eorm roller 42 between plate 36 and vibrator
roller 50. Rider roller 60 in rolling engagement
with form roller 42 is spaced from vibrator roller 58
and also engages outer rider roller 62 which contacts
the surface of vibrator roller 58 as well as rider
roller 60. Independent rider rollers 64 and 66
engage the surface of form roller 42 in spaced rela-
tionship from the other rollers of the distributor
train as is evident from the upper part of Figure 2.
It is again to be noted that the diameters of the
rollers in each independent set of distributor roll-
ers vary to provide surfaces in rolling contact with
form roller 42 which are of different relative sizes.
Also, if non-axially oscillatable drum rollers are
used in lieu of the vibrator roller shown at respec-
tive positions of the schematic depictions of the
drawings it is desirable to substitute vibrator
rollers for at least certain of the rider rollers
associated therewith. If for example, a non-a~ially
oscillatable drum roller is substituted for vibrator
roller 44, it is believed desirable that a vibrator
roller be used in lieu of the rider roller 56. The
same is true as to the other sets of distributor
rollers. If a drum roller of the non-oscillating
type is used in lieu of vibrator rollers 50 and 58,
rollers of the vibrator -type should be used instead
of rider rollers 64 and 66 where a substitution has
been made.
-15- ~-
" ?
,
~13063l~
The image from pJate 36 is transferred to
blanket cylinder 68 which in turn deposits the ink on
web 16 passing therebeneath.
In view of the fact that the planetary inker
train 30b below web 16 is of similar construction to
inker 30a except for relative orientation of the com-
ponents, a detailed description thereof is not necess-
ary, other than to take note of the fact that identi-
cal components have been given the same number with
an "a" thereafter to clistinguish the rollers and
associated components from those of the upper plane-
tary inker train.
The power train for the planetary inker 30
is shown in Figure 3 with the rollers being in the
same orientation depicted i.n the preceding Figure and
on the same scale for a point to point comparison.
Although for purposes of illustration, the main drive
has been shown as comprising a worm 70) it is to be
appreciated that any other type of suitable drive
may be used and depends primarily on the type of
power unit employed for a particular printing machine.
Worm gear 72 in operable meshing relation-
ship to worm 70 is mounted on a shaft 7~ which in
turn carries a gear 76 in clriving relationship to a
train of spur gears which ultimately rotate blanket
cylinders 68 and 68a at the same speed. To this
end, upper blanket cylinder 68 is driven from worm
gear 72 and thereby driven gear 76 through inter-
fitting gears 78, 80 and 82 with the latter driving
a gear 84 on the shaft of blanket cylinder 68. It is
to be noted from Figure 3 that gear 82 is on the shaft
of plate cylincder 3,3 and operably drives a gear 86
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~13~638
on the shaft of form roller 42. In a similar manner,
blanket cylinder 68a is driven through gears 80a in
mesh with gear 76 as well as gear 82a which meshes
with a gear 84a on lower b:Lanket cylinder 68a.
Again the gear 82a is used to drive form roller 42a
through gear 86a which meslles with gear 82a.
Planetary gears 88, 90 and 92 mesh with gear
86 of form roller 42 and serve to drive respective
vibrators 44, 50 and 58 while the lower planetary
gears 88a, 90a and 92a serve to rotate corresponding
vibrators 44a, 50a and 58a.
Sprocket 94 on the shaft of form roller
42 is operably connected to sprocket 96 adjacent ink
fountain 31 by roller chain 98. Gear 100 on the shaft
for gear 96 meshes with gear 102 of ink ball 40. In
the case of the lower planetary inker, sprocket 94a of
form roller 42a is in driving engagement with sprocket
lOOa of ink ball 40a through the medium of roller
chain 98a.
The operation of planetary inker 30 is
believed to be generally evident from the preceding
description, but in amplification thereof, it is to
be appreciated that plate cylinders 38 and 38a as
well as blanket cylinders 68 and 68a are positively
driven at the same surface speed by main worm 70
and that at the same time, form rollers 42 and 42a
are driven at the surface speed of the plates 36 and
36a while planetary vibrator rollers 46, 50 and 58
as well as similar vibrator 44a, 50a, and 58a rotate
at the same surface speed as the form rollers engaged
thereby. Ink balls 40 and 40a are positively driven
from the main drive through roller chains 98 and 98a
-17-
thus assuring accuratje timing of all of the primary
rollers of the ink distribution system. Ductors 46
and 48 as well as 46a and 48a are oscillated back and
forth between positions engaging ink bal.l 40 and
corresponding vibrators 44 and 44a. As will be under-
stood by those skilled in this art, the ductors do
not remain in contact with a corresponding ink ball
for any significant period of time but do contact
a respective vibrator for a significantly longer time
interval. For example, each ductor will remain in
engagement with a respective ink ball only long
enough to place a line of ink along the ductor of
a width of the order of 1/4 to 1/2 in. However, the
ductors will remain in engagement with the primary
vibrator roller associated therewith for at least
one revolution of the ductor and usually somewhat
greater than that. Also, as previously menticned,
the time cycles of the ductors in engagement with the
ink ball and vibrator respectively may be altered by
the operator of the press at will depending upon the
ink demands for a particular job.
~n all instances, two problems which are
presented to printers that require resolution for
each job are done more efficiently with plane-tary
inker 30 -than possible with prior systems and at t
lower cost to the operator.
The inker should not be pattern-dependent,
but capable of providing substantially 100% coverage
of ink at any density needed for an area to be printed.
As can be appreciated, the problem is often complicated
by the fact that one part of the sheet laterally
-18-
J ~':'l;.'l ~
~L~3~)~38 ,
thereof may require delivery of considerably more ink
to the printing plate than the opposite side. This
inherently involves the second problem wherein the
pattern-independent inking system must be functional
without ghosting or the printing will become gradually
lighter in density as the work progresses.
It is for this reason that the single form
rollers used in each of the ink trains of Figure 2 are
not exactly the same size as respective plate cylin-
der. The form roller may be the same size, larger or
smaller than the plate cylinder, with advantageous ~ -
results being obtained in all instances. In view
of the fact that sufficient distributor ro:llers
are provided around the circumference of the form
roller, there is no problem of ghosting under any
print conditions.
Directing primary attention to the upper
planetary inker of perfecting inking system 30, it
can be seen that oscillation of the ductors 46 and
48 between ink ball 40 and vibrator roller 44
causes lines of ink to be transmitted to the surface
of the vibrator for ultimate transfer to the surface
of form roller 42. However, since ductors 46 and
48 remain in engagement with vibrator 44 for at least
one rotation of each of the ductors, the one-quarter
or one-half inch line of ink laid down on a respec-
tive ductor is deposited on the surface of vibrator
48 throughout a substantially wider area, dependant
upon the time of engagement of a corresponding ductor
with the vibrator during rotation of the latter.
The ink on vibrator 48 is divided in half as it
r
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",~
~ 3
contacts the form roller 42 which rotates in the
direction of the arrow illustrated in ~igure 2. Rider
roller 56 picks up a quantity of the ink smoothing
the latter out and acting as a partial supply source
for ink during overall operation of the machine. The
ink again divides between that present on the rider
roller 56 and the surface oE form roller 42 whereupon
the ink delivered as a rep]enishment for that removed,
next comes into engagement with rider roller 54 where
division again occurs with part of the ink being
retained on rider roller 54 while the other half
moves into engagement with vibrator roller 50.
Axial oscillation oE vibra-tor roller 50 serves to
spread the ink end to end of form roller 42 while at
the same time further milling and smoothing the ink.
Rider roller 52 in association with vibrator roller
50 and rider roller 54 acts as a reservoir for ink
while continuing to smooth out the supply which
tends to come in surges by virtue of the ductor oper- ¦
ation of rollers 46 and 48 between ink ball 40 and
vibrator roller 44.
Division of the ink again occurs when
picked up by rider roller 64 and the set of distributor
rollers presented by rider roller 60, rider roller 62
and vibrator roller 58 which operate in the manner
similar to that described with respect to rider
ro].lers 52 and 54 as well as vibrator roller 50.
Final smoothing and division of the ink occurs with ~-
rider roller 66 which is operable against the surface
of form roller 42 independently of the remainder
of the distributor rollers.
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.S: r
f
3'8
As previously mentioned, the relative
sizes of the distributor rollers in the respective
sets thereof is important to functioning of the plane-
tary inker in an unexpected fashion in that there
is no direct overlapping repeat of plate-derived
latent images at any time on any of the rollers
since they are all essentially out of phase because É
of the differences in relative surface areas thereof.
Computer simulation studies have shown that even
though a single form roller is used in association
with the plate cylinder, the overall capacity of
the planetary inker system is greater than with
conventional inking systems heretofore employed,
embodying a substantially larger number of rollers,
and with complete elimination of ghosting because of
successive transfer of latent images from one roller
to another because of inadequate supply of ink to
the plate upon re-contact to the surface of the form
with a particular printing area thereof.
In addition, the planetary inker of this
invention has distinct advantages over prior systems
in that it is substantially more eompact, involves
fewer rollers 7 all of which work with maximum efficiency
and there is less maintenance, and repair required and
clean-up of the press is faster. Furthermore, the
planetary inker especially lends itself to use in a
perfecting press as depicted in Figure 1 since
vertical height is at a premium in a printing tower
which prints on both sides of the paper, thus making
it necessary -to locate the inker train in a minimum
space, particularly from the standpoint of vertical
orientation.
,y~ ,7-
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~L~3~)63~ 1
However, the planetary inker has applica-
tion in one side printing and examples of useful
embodimen-ts of this invention are illustrated in Fig-
ures 4 and 5. Figure 4 shows a single side printing
inker which is identi.cal to that shown in Figure 2,
except that an impression cylinder replaces the blanket
cylinder of the lower printing assembly. In all other
respects, as indicated by -the schematic representa-
tion of Figure 4, the inker train is identical in
construction and operation to that described in detail
above. It is to be appreciated in this respect,
though, that the particular sizes of the rollers is
not critical to successful operation of the unit and
this may be varied as necessary for space requirements
or inking demands of each machine on which the system
is used. Thus, it can be seen in Figure 4 that a
double ductor design is used to transfer ink from the 7
ink ball to the primary vibrator roller in engagement
with the form roller. In Figure 5 on the other hand,
a one sheet printing assembly is illustrated wherein
an impression cylinder is positioned below the blanket
cylinder but in this case with only one ductor being
provided for oscillation between the ink ball and
the primary vibrator roller. ~lthough the double
ductor configuration is preferred from the standpoint
of a more continuous supply of ink to the form roller,
in many instances a single ductor is satisfactory,
particularly where the jobs to be printed do not
normally demand high levels of ink or substa-n-tial
areas of high density. Exemplary in this respect
would be forms presses wherein only limited material
is printed on the sheet in the forms of heaclings, margin
notations and the like.
,.,, ~ ~j,,,. i
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