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Патент USA US2523021

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Sept. 19, 1950
2,523,018
C. L. HENDERSON
METHOD OF CYLINDER ETCHING AND MACHINE THEREFOR
5 Sheets-Sheet 1
Filed Dec. 12‘, 1946
'
INV‘EINTOR.
.
C?eznfes J 1792201615022
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‘BY,
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Sept. 19, 1950
' C. L. HENDERSON
METHOD OF CYLINDER ETCHING AND MACHINE THEREFOR
Filed Dec. 12, 1946
5 Sheets-Sheet 2
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2,523,018
METHOD OF CYLINDER ETCHING AND MACHINE THEREFOR
Filed Dec. 12, 1946
'
s Sheets-Sheet 4
/
‘ sept- 19, 1959
i
c. L. HENDERSON
v
2,523,018
METHOD OF CYLINDER ETCHING AND MACHINE THEREFOR
Filed D60. 12, 1946
'
‘
5 Sheets-Sheet 5
IN VEN TOR.
Patented.
2,523,018
19, p 1950
UNITED; STATES ‘PATENT .QFFICE *
2,523,013
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METHOD OF CYLINDER ETCHINGAND ,
~
MACHINE THEREFOR
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Charles L. Henderson, Appleton, Wis., assignor"
to Paper Patents Company, a corporation of i
.
Wisconsin -
"Application December->12, 1946, Serial No. 715,893 I
,
‘ 6 Claims.
(on. 41-39) _
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'Thei’presentlinvention relates particularly to
improved apparatus‘ and methods for etching
; M intaglio or reiiefprintin'g cylinders.
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.
In intaglio printing the printing surface ‘ordi
narily v‘comprises T. a smooth, metallic surface,
usually of copper, having‘etched therein, sym
The etching machineillustrated in the drawing
‘ is designed particularly for etching printing cylin
ders of standard sizes, and comprises generally a.
relatively heavy frame structure; a pair of bear
ings, adjustably supported on columns, for rotat
‘ ably supporting the printing cylinder which is to
metrically arranged ink-receiving recesses of very
small area. “The-ink recesses ‘throughout the
‘ be etched; means for rotating the printing cylin
‘printing surface are'separated by line-like, un
?uid; means for applying said ?uid to the printing
cylinder; and means for controlling the area on
‘ which the etching ?uid acts and, also, the time
ietched lands‘, which serve to support the doctor
or scraper blade‘ used for removing excess ink
‘from the printing- surface } during ‘the actual
der; a container for ‘the acid or other etching"
of contact between the etching ?uid and the
surface being etched. The means for controlling
the action of the etching ?uid are particularly
‘ The‘ quality of the printing surface is to a large
extent dependent upon the. obtaining of a uni 15 important features of ‘the improved machine. In
effecting this control, barriers of pressure air are
formly etched surface during‘ the etching opera
utilized to/limit the area of'the cylinder subjected
tion. Various methods and procedures have been
developed for etching printing‘surfaces. The
to the etching ?uid, and this same air barrier
is also used to doctor off excess etching ?uid. A
etching machine and‘ the method disclosed in my
a prior Patent 2,360,676 make possible continuous,
water spray is used. to check the action of the
etching ?uid at times when the surface of the
~mecl1anical etching procedures, which are im
‘ portant‘steps forward in the art.
'
cylinder is not in contact with the ?uid. Thus,
The present invention is 'an improvement on
the need for doctor blades or rollers which
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printing operation.
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,
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‘
i the apparatus and method of my prior patent,
mechanically contact the surface to bev etched is
‘‘ and‘ has for its principal object the provision 25 eliminated, and the surface being etched' comes
of a machine and method whereby the‘progress
in contact with only etching‘ ?uid, air and wash
of the etching on the printing surface can be
' closely controlled so that a more uniformly etched
The frame structure illustrated, includes a
heavy rectangular frame Ii which is supported
‘ ‘surface, having very accurate tonal quality, will
be‘ produced. Other‘ objects and advantages of 30 upon upright members IS. The frame members
I I and I3 are desirably of relatively heavy struc
the invention will be made clear by reference to
the accompanying drawings and the following
tural steel and are covered with an acid-resisting
water.-
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coatingat all points where there is possibility of
contact with the etching ?uid. Suitable plat
‘description of one preferred embodiment thereof.
In‘ the drawings,
’
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\ vFig. 1 i; an end elevational view, partially in‘ 35 forms are included on the frame to provide sup
port for the driving motors and other associated
section, of an etching machine constructed in
apparatus.
‘
.
accordancewith the present invention;
, Fig. 2 is a fragmentary side elevationalyview,
An etching ?uid or acid tank l5 extends lon
gitudinally to the frame and is supported at the -
‘l , partially in section, of the etching machine illus
trated in Fig. 1;'
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40
‘
Fig. 3 is a sectional view taken on ‘line 3—3 I
of Fig. 2;
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ends and the various points ‘along its length as
necessary to provide a, rigid structure. The acid
‘tank I 5 is desirably shaped as is illustrated in the
. Fig. 4 is an enlarged, fragmentary, sectional
drawings, and has a-longitudinally extending
view of the improved'etching ?uid control means
shell portion l6 having an arcuate section, I‘!
of the present invention; I
extending for approximately 260° around the bot
tom of the shell I 6 and relatively straight side
'
.
Fig. 5 is a sectional view generally similar to
Fig. 3 showing a modi?ed form of the apparatus
' portions i9 which converge to form a longitudi
Fig. 6 is a view taken on line 6—6 of Fig. 5;
nally extending throat 2| having an opening
about four inches wide. The ends 23 of the
Fig. '7 is a fragmentary, perspective view illus
container 1 5 are plane surfaces and are desirably ‘
of the present invention;
'
i
‘ ‘ trating one means of adapting the apparatus of
] the other ?gures of the drawings for use in con
nection with short printing cylinders, and;
Fig. 8 is a-sectionalview taken on line 8-8 in
Fig. 4.
.
bolted to the longitudinal shell portion IS. The
acid tank ends 23 are adapted to be supported
upon end members of ‘the rectangular frame II.
An acid ‘inlet 25 is provided in the bottom of the
bi) acid tank I5 as illustrated in the drawings. The
2,523,018
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inner portion of the tank l5 and the acid inlet 25
should be covered by a suitable acid-resisting
material as, for example, a ‘A; inch coating of
acid tank l5, and is large enough to allow for the
free circulation of air around the outside of the
acid ‘tank as is shown by the arrows 51. The'
pure black gum rubber or a suitable acid-resisting
air inlet 59 to the jacket 55 is conveniently pro
paint or cement.
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vided at the bottom portion of the jacket 55 and
A large circular portion, indicated at 22, is cut
a heavy duty, centrifugal blower 5| is supported
out of each of the end sections 23 to provide
adjacent the air inlet 59 for ‘supplying the needed
a means of access to the interior of the acid tank
pressure air.' An outlet pipe 63 is provided at
l5 and means for removing or servicing an im
each end of the air jacket to connect the coni
peller member 29 which is to be hereinafter de 10 cal bearing seal 34, before described, with a source
scribed in detail. The openings resulting from
of pressure air. The blower 6| is adapted to be
the cut-out portions 22 are sealed by removable
powered by a motor 65 and both the motor. 65
plate members 3| which contain bearings 33 for
and-the blower 5| are supported on a suitable
rotatably supporting the shaft for the impeller
frame 51.
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29. A seal between the plate members 3| and, 15' Two longitudinally extending air nozzles or
the end sections 23 of the acid container‘ I5 is
slots 69 are formed between the outside surface
provided by inserting a rubber gasket 35 between
of the acid tank |5 and theinner surface of the
the plate members 3| and the end sections 23
air jacket 55 by means of longitudinally extend
of the acid tank 15. The gasket 35 acts as an
ing structural members 1| and 13 shaped as shown
extension of the rubber or other acid proof coat 20 in the drawings (Figs. 3 and 4). The members
ing provided on the inner surface of the acid
1| and 13 are joined by a series of counter-sunk
container and thus insures that the metal will
machine screws 15 which are adapted to engage
not be exposed to the action of the etching ?uid.
threaded holes in the inner member 13. The
The acid, or other etching ?uid, indicated in
members 1| and 13 are maintained in their rela
Fig. 3 at 21, is atomized and applied to the sur
tive positions by means of adjusting screws 11
face which is to be etched by means of a rotat
which are threaded into the outer member 1|
able impeller member 29 which is desirably pro
and which have extensions adapted to press upon
vided with a de?ector 31. The de?ector 31, if
the upper walls IQ, of the acid container l5, and
used, may comprise a longitudinally extending
on the inner structural member 13.
arcuate member (about 90°) which isattached 30 Adjusting the pairs of screws 15 and 11 thus
to the bearing members 33 by means of brackets
provides a convenient means for carefully adjust~
34 at each end of the acid tank l5, in a posi
ing the width of the air nozzles or slots 59. The
tion adapted to direct the acid thrown from the
inner members 13 are attachedto the ends of. the
impeller 29 against the surface to be etched. The
acid tank I5 and to the frame H by means of
de?ector 31 may be fabricated from steel and
machine screws 19 and, thus, provide additional
coated with a suitable acid-resisting material, or
longitudinal stiffening of the structure. The in
it may be fabricated from acid-resisting plastic
ner members 13 are shaped as shown in the draw
or the like. The impeller 29 of the apparatus il
ings ‘so as to provide a throat 8| having parallel
lustrated in the drawings comprises a series of
walls 83 and 85 for guiding the etching fluid spray
paddle members 39 made from an acid-resist 40 against the surface to be etched as indicated
ing plastic such as that sold under the trade
by the arrow 81 in Fig. 4. .
name of Lucite, or some other acid-resisting ma
A water pipeline 89 is supported on the frame
terial. The paddle members 3| are affixed to a
H by brackets 9| and extends longitudinally in
suitable rotatable shaft 4|; one end of the shaft
close proximity to-the air slot 69. The water pipe
4| extends through an opening in one end of the
line 89 has a continuous slot 93 on the inner side
acid tank l5 for connection to a motor 46 or
adapted to direct water from the pipeline 83 onto
other rotating means, as illustrated in Fig. 2.
the surface of the cylinder 95, thus halting the
The impeller 29 is supported for free, high speed
etching action on all sections of the cylinder not
rotation within the acid container |5 by suitable
in immediate contact with the atomized etching
bearings 33 (Fig. 2). The impeller shaft 4| has
?uid. Drain trays 91 are provided on each side
an enlarged baille portion.45, intermediate the
of the structure between the air jacket 55 and
ends of the paddle members ‘39 and the end of
the outer frame members ||. The trays 91 may
the shaft 4|, which is adapted to cooperate with
be fabricated from sheet metal and are, if pro
a cone-shaped bearing seal 34a through which
vided with a drain outlet 99, connected to a sewer
a stream of pressure air is passed. The bearings
or other disposal means. The outerlongitudinal
33 are thus protected from the corrosive action
air slot members 1| are shaped with an added
of the etching ?uid by the stream of pressure air
?anged portion | 0| adapted‘ to provide a leak
which sweeps all foreign materials out of the
proof bond between the member 1| and the drain
protecting cone 34.
trays 91 (Fig. 4).
‘
The motor 46 which is used for rotating the
In order to control the. level of the etching
impeller 29 is supported on a bracket 41 affixed
?uid 21 in the acid tank l5, an adjustable height,
to the frame upright l3, and is connected to the
filling-container I03 is provided. This is re
impeller shaft 4| by a belt 49 and suitable pulleys
movably fastened to a bracket “14 on the frame
5| and 53. A constant‘speed motor with variable
l3 and is connected to the inlet 25 of the acid
speed pulleys is desirable, so that the atomization 65 container l5 by means of a gum rubber or other
of the acid may be closely controlled. The im
acid-resisting, ?exible hose I06. All the surfaces
peller 29 should be rotated at relatively high
of the ?lling-container I03 are covered with an
speed in order to accomplish good atomization
acid-resisting coating. It is advantageous if one
and an even distribution of the etching ?uid along
of the sides of the container I03 is formed into
the surface which is to be etched. Impeller speeds 70 a spout or guide “)8 so that the etching solution
upwards of about 1200 R. P. M. have been found
may be conveniently poured from the ?lling con
to be satisfactory.
tainer I03 when it is desired to drain the acid
The acid tank I5 is surrounded by an air jacket
from the main acid tank l5.
55 fabricated from sheet material. The air jacket
As printing cylinders vary considerably in
55 is shaped to conform with the shape of the 76 length and in diameter, a cylinder etching ma
2,528,018
‘chine should include means ‘for ‘accommodating
diate the opening of the air slot 99 and the cylin
cylinders‘ of varying dimensions as is shown in
Fig. 3 as 95 and 95a.__ In the particular machine
; shownlin the ‘drawings, this means includes an
adjustable bearing support structure for the cyl
inder 95 which is to be etched. This structure in
cludes two screw jack members I95 actuated by
knurled knobs II". The jacks I95 are rigidly at
der 95 effectively-con?nes the acid spray to the
. areas‘ of the cylinder directly above the slot 9|
in the acid tank I5. The air also keeps the water
‘spray from entering the acid tank I5 and dilut
. ing the acid.
In operation, one section of the
cylinder 95 passes through the acid solution
spray, the acid solution is doctored off by the
air blast from the adjacent'slot, the surface is
tached at each end of the frame I I. . An extensi
ble portion I99 of each jack I05 terminates in a 10 then washed with water, and the cylinder 95 io
tates around to the second air slot where it may
rings II 3 which are slipped over the ends of the
be partially dried by the blast and again enters
printing. cylinder shaft I I5 to facilitate rotatable
the ‘acid spray. The excess wash water runs
movement“ The adjustment of thedistance be-‘
down the two drain trays 9‘Ii and out the drain
yoke section, I II adapted to support ball bearing
tween the surface of the‘cylinder being etched
pipe provided.
portant adjustment in the successful operation
of‘ the etching machine. For this reason, the jack
members I95, desirably have low-pitch threads so
that the g‘ap.between air slot 69 and the cylinder.
95 may be closely adjusted. Usually a spacing
of from‘ about 1*q_to% of an inch will be. found
satisfactory in the illustrated I apparatus.
In
place of ‘the knurled manual adjustment knobs
I91, hydraulic or power actuated jacks maybe
The motor 43 for rotating the cylinder 95
which is to be etched is adjustably supported on
the frame I I by a sliding plate member I I 'I which
be found desirable to partially cover both ends
of the impeller housing with an acid-resisting
removable ba?ie I21 as illustrated in Fig. "I. The
20, baiiie I2‘! is desirably a plate of Lucite or‘ other
acid resisting plastic which is held in position
by means of' cross members I29 and bolt and
wing nut assembly I3I. This arrangement con
flnes the discharge of the etching ?uid to the
25 length of the cylinder which is to be etched. The
wash water is con?ned along an‘ ‘equivalent
length of the water pipeline 89 by means of a
removable sleevelmember I33 which is held in
pgsligion by a strap locking means‘as shown
may be moved back and forth along a line nor ill)
mal to vthe cylinder shaft H5 so as to tighten or
loosen a driving belt H9. .The sliding plate H1
is locked in by means‘ of a screw locking means.
III. A pulley I23 on the motor drive shaft is
operatively connected to a pulley I25 which is :
adapted to fit on the cylinder shaft I I 5 by means
of the belt H9. During the actual etching opera
tion, it is ‘desirable that the printing cylinder 95
which is to be etched'should be rotated at a rela
tively low speed. Tests indicate the linear speed
of the surface being etched should‘ be within the
'
When etching relatively short cylinders, it will
V and the outlet of the‘ air slots 69 is a most im
a
5.
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The modi?ed form of the apparatus illustrated
‘ ' in Figs. 5 and 6 is essentially similar to ‘the ma
chine which has been described in the forego
ing, with this one important exception:
In the modi?ed apparatus, the etching ?uid is
directed against the surface to be etched‘by
means of a liquid jet atomizing structure I31
which is operated by a plurality of spaced air
jets. The atomizing structure I31 includes a
pair of complementary, machined plate members
I39 which are designed so as to provide a plu
range of from about 25 to 40 feet per minute. For ‘
rality of regularly spaced atomizing 'jet cham
a cylinderlO inches in diameter, this requires
~bers Ill which open into wedge-shaped throats
that it be rotated‘ at from 1.0 vto 15 R. P. M. , r
I43 wherein are disposed de?ector members I45
‘ To start‘ the machine in operation, the acid or 45 for dividing and directing the atomized ‘stream
other etching ?uid is poured into the ?lling con
so as to assure full coverage at the open upper
tainer I03 until the liquid level in the acid tank
. I5 ‘is high enough to ‘allow the impeller blades 39
end'of the throat. ‘The complementary plate
members ‘I39 are bolted together and are held
to dip into the acid about 1/; inch at the lowest
inplace within the acid tank I5a by means of
.postion in their are of travel. The cylinder 95 50 cleats or the like (not shown). A jet tube I49
which‘ has‘the ball bearing rings H3 in place on
is provided in each of the atomizing chambers
its sh’aft" H5, is cradled in the yokes III .pro- I HI and this tube. is connected to a suitable source
vidéd for thebearings I I3 on the adjustable sup
of pressure air through a conduit I5I. Particu
porting members I09. The height of the yokes
III is adjusted so that the gap between theair
slot‘ 59 and the surface of the cylinder 95 is from
using a jet tube having an ori?ce about 1*; inch
in diameter and an'air pressure of about 15 pounds
about 114* to ‘A; of an inch. The cylinder driving
per square inch gauge. ‘ ‘The air slots 69a, the
motor 43 is energized and the speed of rotation
is adjusted to conform with the etching condi
outer'air jacket 55a, the water pipeline 89a,
and the vertically adjustable support means for
the cylinder‘which is to be etched are exactly
the same in this apparatus as in the previously
tions required. The air blower 6| is started and
then the “spray from the water pipeline 89 is
turned‘on. The impeller 29 is energized and its
speed‘is adjusted to provide the most desirable
atomization of the etching ‘solution 21.
The ‘
etching is continued u°ntil the ink receiving re
cesses havebeen etched to‘ the required depth
and then the impeller 29 is stopped and the cylin
der is rotatedin the water spray and air blast.
After the surface of the cylinder 95 is thoroughly
larly satisfactory results have been obtained when
described structure.
‘
'
Tests have shown that the etching apparatus
which has been described in the foregoing, is
‘capable of producing gravure cylinders of par
ticularly high quality. The contact between‘
etching ?uid and the rotating cylinder is closely
controlled by the doctoring action of the air
blasts and by the dilution of the etching solu~
washed, the water from the manifold 89 may be 70 tion by the wash\water. The finest lands or
,turned olf‘and ‘the cylinder 95 may be rotated in
raised dots. are freed from all mechanical con-'
_. the air blast from the slots 69 to dry it off.
It has been found that‘ a’ pressure differential
tact and are subjected only to the acid spray, the
pressure air barrier, ‘and the water spray.‘ Thus
of from about 1 to 5 pounds per square inch - ‘ the improved method of the present invention
across the pressure air barrier located interme- 75 accomplishes the highly desirable function of
2,523,018
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7
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8
,
making it possible to carry out the continuous
and emcient etching and washing of printing‘
surfaces.
face of the cylinder, the air-jet-projecting-means
being located between the mouth of the trough
The features of- my invention that are be
lieved to be new are expressly set forth in the
5. In combination in an etchingmachine for
etching the peripheral surface of a printing cyl
inder, means for supporting the cylinder to be
etched for rotation about a generally horizontal
appended claims.
Iclaim:
.
and the water-projecting-means. _
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1. The method for etching cylinders wherein
axis, a trough having a narrow, longitudinally
longitudinal segments of the surface of the cylin
extending, open mouth whose major axis is gen
der are consecutively subjected to an etching 10 erally parallel with the axis of rotation of the
?uid spray, an air blast for doctoring off said
cylinder to be etched, the trough and cylinder
etching ?uid, a water spray, and an air blast for _
being so supported and related that the pe
doctoring oil the excess water, said steps being
ripheral surface of the cylinder although out of
repeated until the surface of the cylinder is com
pletely etched.
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2. In an etching machine, means providing an
contact with the trough provides an effective
15 closure for the open mouth, means for ‘projecting
etching liquid in the trough against that portion
of the peripheral surface of the cylinder which
closes the mouth, means for rotating the cyl
inder to cansesuccessive portions of the pe
etching zone, means de?ning a ?rst air doctor
zone, means de?ning a washing zone, means de
lining a second‘ air doctor zone, and a source of
pressure air connected to said ?rst ‘and said sec 20 ripheral surface of the cylinder to move out of
ond air doctor zones, said etching zone being lo
register with the open ‘mouth, means for pro
cated intermediate said air doctor zones and said
jecting air jets against the peripheral" surface
washing zone being located adjacent said second
air doctor zone, and means for repeatedly pass
of the cylinder, the air-jet-projecting-means
being positioned to bound the sides of the mouth
ing the surface to be ' etched consecutively 25 which are parallel to the major axis thereof,
through said zones in a manner such that said
and means for projecting water against the pe
surface is successively and repeatedly exposed
ripheral surface of the cylinder outside of the
to said ?rst air doctor zone, said etching zone,
trough'inimediately after it has moved out of
said second air doctor zone, and said washing
register with the mouth and the air-jet-pro
zone.
80 jecting-means which bounds the side of the
3. In combination in an etching machine for
mouth.
’
etching the ‘peripheral surface of aprinting cyl
inder, means for supporting the cylinder to be
etched for rotation about a generally horizontal
axis, a trough having a narrow, longitudinally
extending, open mouth whose major axis is gen
erally parallel with the axis of rotation of the
6. In combination in an etching machine for
, etching the peripheral surface of a printing cyl
inder, means for supporting the'cylinder to be
etched for rotation about a generally horizontal
axis, a trough having a narrow, longitudinally
‘ extending open mouth whose major axis is gen
cylinder to be etched, the trough andv cylinder
erally parallel with the axis of rotation of the
being so supported and related that the periph
cylinder to be etched, the trough and cylinder
eral surface of the cylinder although out of con 40 being so supported and related that the pe
tact with‘the trough provides an effective closure
ripheral surface of the cylinder although out of
for the open mouth, means for projecting etch
contact with the trough provides an effective
ing liquid in the trough against that portion'of
closure for the open mouth, means for pro
the peripheral surface of the cylinder which closes
jecting etching liquid in the trough against that
the mouth,‘ means for rotating the cylinder to 45 portion of the peripheral surface of the cyl
'cause successive portions of the peripheral sur
inder which closes the mouth, means disposed
face of the cylinder to move out of register with
along each of the sides of the trough which are
the open mouth, means .for projecting water
parallel to the major axis thereof, for projecting
against the peripheral surface of the cylinder
an elongated air jet against the peripheral sur
outside of the trough after it has moved out of 50 face of the cylinder, means for rotating the cyl
register with the mouth, and means for discharg
inder to cause successive portions of the pe~
ing. an air jet against the peripheral surface of
ripheral surface of the cylinder to move out of
the cylinder.
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register with the open mouth, and across the
4. In combination in an etching machine for
air-jet-projecting-means, and means for .con
etching the peripheral surface of a printing cyl
tinuously
projecting water against the peripheral
55
inder, means for supporting the cylinder to'be
surface of the cylinder along its entire length
etched for rotation about a generally horizontal
after it has moved out of register with the
axis, a trough having a. narrow, longitudinally
' extending, open mouth whose major axis is gen
erally parallel with the axisof rotation of the ~
cylinder to be etched, the trough and cylinder
being so supported and related that the periph
eral surface of the cylinder although out of con
tact with the trough provides an effective clo
mouth.
"‘
CHARLES L. HENDERSON.
REFERENCES CITED
The following references are of record in the
?le of this patent:
etching liquid in the trough against that portion 65
UNITED STATES PATENTS
of the peripheral surface of the cylinder which
Number
Name
Date
sure for the open mouth, means for projecting
closes the mouth, means for rotating the cylinder
to cause successive portions of the peripheral sur
face of the cylinder to move out of register with 70
the open mouth, means for projecting water
against the peripheral surface of the cylinder out
side of the trough after it has moved out of
register with the mouth, and means for pro
jecting an air'jet against the peripheral sur 75
590,966
1,166,378
Cornwall ________ __ Oct. 5, 1897
Levy ____________ __ Dec. 28, 1915
2,293,201
Gaebel __7 _______ __ Aug. 18,1942
2,360,676
Henderson ______ __ Oct. 17, 1944
FOREIGN PATENTS
Number
229,956
_ Country
Date
.
Great Britain _____ __ Mar. 5, 1925
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