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Патент USA US2127824

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Aug. 23, 193s.
Filed April 1751928
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Patented Aug. 23, 193s .
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August A. Leuchter, Augusta, Maine
Application April >1'7, 1928, Serial No. 270,639
5 Claims. (Cl. 101-_-401)
Intaglio or rotary photogravure printing is
mostly done from cylindrical surfaces, each of
Such cylinders chiefly consisting of an iron core,
mounted upon a steel shaft, and carrying on its
5 outer periphery a. layer of’copper, which when
ground and polished to perfection, is etched upon.
and serves then as the actual printing-surface
of such cylinders.
Usually such layers of copper are produced
bring about such condition of a substantially
disconnected electrolytic deposit, the cylinder
body is purposely prepared in such a way, by
either oxidizing its surface or otherwise laying
on an interference film, that the growing-fast 5N
of such an on-coming electrolytic deposit to the
cylinder body is positively prevented in the proc
ess of electro-deposition.
While such and other similar methods pos
10 by electrolytic deposition directly upon the iron
body or core of such cylinders, and are carried
to a thickness suitable for receiving from twenty
to thirty etching in succession. Under the gen-
readily detachable shell-like deposit, and vdo fa
cilitate the stripping-off of the deposit whenever
its removal is desired, certain distinct disadvan
-eral proceedings‘of carrying out the successive
tages are entailed by such methods, inasmuch as
l5`etchings upon vsaid outer layers of copper, it is
customary to remove an etched-in-surface, bear-
sibly offer certain advantages by producing a l0
a printing surface, and especially an intaglio 15
one, shouldl have an absolute tight and solid
ing images to be reproduced by what is known connection throughout with the underlying cyl
as “gravure" or intaglio-printing, by the process
of grinding and afterwards re-polishing the face
20 0f said layer of copper in order to receive the
next etching.
inder-body, because in the process of printing
from such a cylinder, commonly known as roto
gTavure printing, considerable pressure is ex- 20
erted by the impression-roller against the etched
Under this commonly _general procedure .the
surface of the printing cylinder in order to force '
diameter of such ` printing-cylinders is being
the paper, passing between them„most thorough
constantly reduced for such successive etchings,v
_ly down into the depressions .of the etchings,
25 and it is not possible therefore to retain any
in order to receive the full value of tone-grada- 25 I
iìxed standard diameters of cylinders, except a tion by the varying density of ink carried in thc
ground-olf outer section, which had carried a etched-in images of the printing surface.
previous etching, were re-built, and thus the cylSince best results can only be had in intaglio
inder brought back to Vits former diameter by an or rotary photogravure printing by exerting con
30 additional deposit of copper.
siderable pressure against the printing-cylinder, 30
Since it is highly desirable to maintain a fixed it is clearly obvious that a loosely laid-on shell,
standard diameter for such printing cylinders, lWithOllt any intimate and Solid Connection With
and to avoid the .process of grinding-oil' used the Vunderlying cylinder-bodl/„Can not present
printing surfaces, and gradually re-ñnishing the an ideal printing surface, kconsidering the press
35 newly exposed copper surface to make it suitable
OperatiOn 8.10116. but Other and greater Objeû‘ 35
Jfor receiving a 4IEW etching thereon, but at the
tionable features are present ywhen the _etching
required expenditure of from eight to ten hours
and preparation of the printing surface in gen
oi' time‘and effort, different means~ have been
eral is carried out.
suggested and devised to dispose of such used
In such latter operation, in order to get best I
40 printing surfaces, and to replace them in much o effects, considerable retouching, tooling,_ re-en- 40
l shorter time by new deposits of the same thick- , graving and the like are commonly practiced,
ness, thereafter made ready to lreceive a new
One of `such means, embodies a method Where45 by a thin layer 0f Copper is deposited upon the
cylinder body without becoming solidly attached
t0 the Same. except at the two extreme ends of
the cylinder, but otherwise forming a loose detachable shell extending all over the periphery
50 of the cylinder, which feature enables the removal of such a shell by shaving or cutting
through the two extreme solidly connected ends
of the same, whereupon such shell can be readily
removed from the cylinder body by peeling, after
55 a lengthwise incision is made in the same.
and must be resorted to, and such work is nat
urally more safely and practically carried out on
a solidly connected layer of copper than on a
loose shell, where there is always danger of cut- 45
ting-through in any operation of hand-tooling,
or the-loosening of such a shell in spots by burn
ishing, or by having any ink work its way un
derneath through any possible pores in sucha
shell-deposit, and eventually may causea loosen- 5°
ing or buckling of such deposit in the process of
It is for this reason that such method of
preparing and producing of printing surfaces by
means of a detachable shell has not met with u
‘ approval and is more or less objected to when
cylinders for intaglio-printing in color are to be
prepared, involving far more .exacting conditions
and more retouching in order to reach desired
effects in the varyingï depths of the etching.
Therefore it is one purpose of the present in
vention to overcome and eliminate all such ob
jectionable features and deficiencies entailed by
the practice of a loosely laid-on shell-deposit to
10 form the actual printing surface of a cylinder,
, and to produce by a different proceeding a print
ing surface of an electrolytically deposited layer
of copper of suitable thickness to receive and
carry an intaglio etching; but such layer of cop
15 per is so intimately and tightly deposited onto
another layer of a hard metal, which forms the
outer periphery of the cylinder body, that re
moval of the deposited layer of copper is not pos
sible by any mechanical stripping method, but
~ could only be accomplished by either grinding,
or turning-off in a lathe, or else by electrochem
ical dissolution in an electrolyte, or by other
chemical disintegration in reconverting the me
tallic copper into a copper-salt or oxide.
While I have under my newly devised method
of producing removable printing surfaces, either
cylindrical or flat, a choice of three distinctly dif
ferent ways to effect such removal, I prefer the
one of electro-chemical dissolution as the most
practical and economical one, whereby I am en
abled to re-deposit the copper-layer from the cyl
inder surface back onto the anode plate, thus
saving from eighty to eighty-five per cent. of
the originally deposited copper, that is, of the
le, layer first deposited to form the printing sur
face on the cylinder; and naturally such saving
of copper repeatedly takes place every time a
used printing-surface is removed to become re
placed by a new deposit.
With such objects in view, my invention con
sists of novel features in the printing member,
such as cylindrical or flat, and in certain process
steps, to be hereinafter described and then
claimed, with reference to, the accompanying
: drawing, illustrating the invention as prefer
ably applied to a printing cylinder, and in which:
Figure 1 is a longitudinal section before the
.copper deposit is formed, and
Fig. 2 is a similar section after the deposit
has been made.
In the drawing, a steel shaft 5 has the core
6 of the printing cylinder mounted and fixed
therein in suitable well known manner. This is
but one form of printing cylinder to which the
55 invention may be applied.
To make the removal of a used printing sur
face possible by electro-chemical dissolution of
the copper, and in this way convert it back onto
theanode-plate, it is necessary to carry on the
cylinder body 6, and to constitute the' base for
the final layer-of copper forming the actual
printing surface, a layer 1 of hard metal, capable
of receiving and mechanically and intimately
combining with the on-corning electrolytic de
65 posit at the time such final layer 8 of copper is
grown thereon by electro-deposition; and also on
the other hand, when the removal of such body 8
of copper is undertaken by electrolytic action,
said layer 1 of hard metal must also be capable
70 of resisting corrosion and dissolution in the
electrolyte under the influence of the reversed
current, when this layer 1 of hard metal must
then actually serve as an insoluble anode, and
remain immune to any reaction of both the cur
rent as well as the copper-electrolyte usually em
ployed. The electrolyte is the usual acid copper
bath. The speed of rotation of the cylinder
during electro-chemical treatment may approxi
mate 200 revolutions per minute, for example.
Since a used intaglio printing surface natural
ly consists of an unevenly-thick layer 8 of cop
per, due to the fact that the same carries the
etched-in images of varying depths, it follows
that in the course of electrolytic dissolution the
etched-in sections of such layer of copper be
come dissolved first, by reason of being thinner,
thereby exposing the layer 'l of hard metal un
derneath in those sections, and which now must
remain unaffected, while gradually the copper is
being dissolved completely all over, the thicker
sections taking the longest.
When all traces of the copper layer 8 have
disappeared, and the layer l of hard metal is
now completely exposed, it is only necessary to
break the reversed current connection, under 20
which the cylinder had been made the anode
terminal, and the anode-plate been the cathode
terminal in the electrolyte, and after brushing
the cylinder with the hard metal layer, all bare
on its outer surface, clean from any scum or foam 25
of a gaseous formation, a new deposit may be
formed again immediately, by throwing the re
versible current switch back into its normal po
sition, when thereby normal current connections
become reestablished in the depositing-tank, and 30
the cylinder is made again the cathode-terminal
in the depositing solution, and copper-depositing
proceeds again onto said layer of hard metal
'l until the desired thickness of copper layer 8 is
reached, which latter is determined by the am 35
pere-amount of current flowing in a given pe
riod of time.
As this layer of hard metal remains entirely
unaffected by any reaction of either current or
depositing solution, no change in size of cylinder 40
body will take place, thereby assuring standardiz
ing sizes of cylinders, which under the old method
of grinding olf the used printing surfaces and
thereafter re-ñnishing, to facilitate etching-on of
new printing-images, was not possible, but causes 45
constant reducing of cylinder sizes with every new
etching effected thereon.
Summing up the foregoing it becomes evident '
that the outstanding feature of this invention is
an absolutely solid and perfectly united non-. 50
stripping layer of copper on the outer surface of a
cylinder body, whereon all the usual operations of
etching, retouching and tooling, as become neces
sary in the preparation of intaglio printing sur
faces, may be carried out with utmost security 55
and no danger of causing the said thin layer of
copper to come loose or lift from the cylinder
body; neither would any amount of pressure in
the printing operation have any detrimental
stretching effect on same, nor could even a local
grinding operation effect a loosening of its hold on
the underlying body.
In making an individual deposit for every etch
ing, only a thin layer is necessary, requiring at
best only polishing; and due to the fact that the 65
removal of the used printing face can be accom
plished by electrochemical dissolution, and there
by the layer of copper be transferred from the
cylinder back onto the anode-plate, and as the
same would be repeated with every renewal of the 70
printing face of a cylinder, a great saving of
copper is realized especially in the continuous run.
For example, the thickness of the copper may be
from three to six thousandths of an inch, and the
hard base preferably thicker.
All such achievements are solely due and pos
sible only by the creation of a layer 'I of hard and
this necessarily hard and impervious layer of
Cl softer metals the latter may consist of, and be
there also it is obligatory to deposit a heavy
enough layer of such metal; so thatthe- pushing
and pulling power of the electric current passing
through the cylinder-body and on towards the
cathode surface, in its very act of dislodging and
by the use of nickel, or a combination there
impervious metal completely encasing the iron 'metal
traces-of chromium or platinum injected;
core 6 of the cylinder body, or such other layers of
directly underneath and adjacent to the final
layer of copper, which has to serve as the actual
printing surface of a cylinder.
'I’he evident purpose of this layer 'l of hard
dissolving said copper layer by electrolytic proc
impervious metal, preferably consisting of nickel,
or a combination thereof to increase the corrosive >
resistance, is to form a permanent base for the
layer of copper constituting the actual printing
surface, with which it must most intimately unite;
but also on the other hand the base layer ’I must
serve as a positive protection against corrosion
and disintegration of the- cylinder body, of which
it is a. most vital part, when dissolution of the
copper layer is enacted and carried out by the
electro-chemical process for the purpose of re
moving a used printing surface.
In creating such a layer 1 of impervious hard
metal the invention is not conñned to the employ
ment of nickel, but there could be used any other
metal capable of resisting the corrosive action of
the copper electrolyte combined with the in
fluence of the reversed electric current, under
which condition the cylinder-body actually be
' comes the anode-terminal, and must then assume
all properties of an insoluble anode, as soon as any
etched sections of the copper-layer have yielded
to electro-chemical dissolution, and the layer of
the impervious metal underneath becomes ex
posed, since it is only in such way that the disin
tegration of the cylinder-body below said final
layer of copper is positively prevented, and thus a
permanent unaffected base for said outer layer of
copper is created.
Other metals of like corrosion resisting property
40. that might be considered for such purpose would
be chromium, platinum and also lead, but it is
preferred not to use either of these for the
reason of being highly expensive, as is the cost of
platinum, or a perfect union with the final layer
of copper is not possible, but might only be used
when a detachable copper-shell Ais desired with a
view of stripping or peeling-oli' bodily; and finally
a layer of lead is at best only a very soft body and
very difficult to maintain in perfect physical con
dition, especially when considering that one prin
cipal requirement of this invention is the creation
of a hard impervious layer of metal, capable of
being brought to a true and high finish and so
maintained during the continuous practice of
building-on and taking-off said layers of copper,
serving as printing-surfaces of cylinders.-
Besides, layers of such other metals are diilìcult
to produce in the required thickness but answer at
best for a light plating'only, which would prove
60 useless for this purpose, because, while in such
state they might temporarily resist the corrosive
action of the copperelectrolyte, they could not
resist the powerful influence of the electric cur
rent passing through the cylinder body `as an
anode and outwardly therefrom towards the cath
ode surface, and due to which tendency there is
caused a loosening and lifting-up of any such
lightly plated film or pellicle of the respective
metal, and then of course, the cylinder-body
would no longer represent an insoluble anode, but
be subject to attack and disintegration, thereby
ruining the same, and making the whole operation
of removing such an outer copper-film a complete
-This very same tendency prevails in creating
ess, has no longer- any such ruinous effect on the 10
layer of nickel.
. It is evident therefore that Whichever corrosion
resistance metal is used for creating such an im
pervious metallic layer, the same must be carried
to such thickness that the powerful _iniiuence of
the reverse flowing current can have no loosening
or lifting influence on such _a layer, and cannot
disturb the same in the least.
'I‘herefore it is preferred to create such im
pervious metallic la'yer of nickel, as that is reas 20
onable in cost, and the electro-deposition of the
same can be carried to any ,desired and almost
unlimited thickness with ease, and furthermore
nickel possesses great tensile strength besides
hardness, and may be turned or ground true, and
also brought to a high surface-finish, which it is
apt to retain due ‘to its hard and non-corrosive
nature, and in general it is the ideal metal for
this very purpose.
The encasing of the cylinder-body with nickel 30
is even carried to vfar greater‘thickness than it is
necessary to resist any detrimental current action,
for the reason that it affords and brings about
greater rigidity of the cylinder-body, usually con
sisting of cast iron and copper, and thereby pre
vents any sinking of sections of the cylinder
periphery, and in general helps to keep the cylin
der in perfect shape and true condition.
What I claim as new, is:
1. A printing member having a permanent base 40
of hard, impervious, non-corrosive metal, and a
thin outer layer of a different kind of metal for
providing a rotary photogravure printing surface
and which throughout its entire area is intimately
and solidly united with such base, and which layer 45
is- of a character suitable for etching such print
ing surface, the outer layer being sensitive to
electrolytic dissolution of its _metal and the metal
of the base being neutral thereto.
2. A printing member, including >a main body,
a layer of hard, impervious, non-corrosive metal -50
intimately united with the body, and forming a
permanent base, and an exterior thin layer of
softer metal for providing a rotary photogravure
printing surface and which is intimately andl
solidly united throughout with such base, and 55
which'exterior layer is of a character suitable for
etching such printing surface, the exterior layerbeing sensitive to electrolytic dissolution of its
metal and the metal of the base being neutral 60
3. A printing member, including a main body, a
layer of hard, impervious, non-corrosive metal
intimately united with the body, and forming a
permanent base, and an exterior thin layer of
copper for providing a rotary photogravure print
ing surface and which throughout is intimately
and solidly united with the base by electro
deposition, and which exterior layer is of a char
acter suitable for etching such printing surface, 70
the exterior layer being sensitive to electrolytic
dissolution of its metal and the metal of the base
being neutral thereto.
y 4. A printing cylinder, including a core, a shaft
on which it is ñtted, a layer of hard, impervious,
non-corrosive metal extending all over the cy
lindrical surface and ends of the core, and an
exterior layer of copper intimately united with the
layer of hard and non-corrosive metal by electro
CH deposition throughout the whole surface area of
the hard, non-corrosive layer, and the cylindrical
surface of the copper layer being of a character
suitable to provide a rotary photogravure print
ing surface.
5. A printing member having a main body with
a permanent nickel base electro-deposited there
on, and an exterior thin layer of copper directly
electro-deposited on the base, and which depos
ited layer of copper has a depth slightly more
than sufficient for one etching, and is of a char
acter suitable to provide a rotary photogravure
printing surface and throughout is intimately and
solidly united with the outer surface of such base,
the base being the harder of the two metals.
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