Improvements in or relating to Processes and Apparatus for Obtaining and Depositing Metals by Electrolysis, and in the Treatment of the Metals after Leaving the Electrolytic Bath.
Year: 1893

page_text: Date of Application, 13th Dec., 1893.
Complete Specification Left. 1st Aug., 1894-Accepted. 1st Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to Processes and Apparatus for
Obtaining and Depositing Metals by Electrolysis, and in the
Treatment of the Metals after Leaving the Electrolytic Bath.
1, ERNEST STOULS of 16 Rue Drouot, Paris, France, Engineer, do hereby
declare the nature of this invention to be as follows:-
For some years electrolysis has been employed in the manufacture of metals for
industrial purposes.
The processes as actually worked give good results in the case of gilding.
silvering and electro-plating, that is to say when the deposit of metal is of slight
thickness; they are, however, not so satisfactory when it is require to produce a
particular kind of metal, and to obtain, as the Elmore process is particularly
adapted to obtain, a layer of metal thick enough to be afterwards worked, and to
receive the various industrial adaptations of which it is capable.
&S
My invention has for its object various improvements in electrolytic metallurgy
avoiding the drawbacks at present existing, so that a manufacture is obtained
sufficiently uniform to produce results the homogeneity of which is as perfect
possible, whatever may be the thickness of the layer of deposited metal. These
improvements, which relate either to different phases of the work itself or to the
material employed in its execution, have principally for object modifications of the
mandrels, moulds, cores or cathodes, of the means of covering them with plumbago,
and of the apparatus for giving them motion; methods of purifying the solutions
of metallic salts used in the manufacture, and lastly, additions and modifications as
regards the working or manipulation of metals on leaving the electrolytic bath.
In the first place the mandrels, moulds and cores, whether of iron, steel, copper
or other material have hitherto been made in a manner absolutely defective. The
mandrels of cast iron have had, for example, foundations of the same metal, or
again fittings of bronze, which in a little time are rendered useless on account of
defects in their construction or because the acids which attack the foundations
of these mandrels, also deteriorate the liquor. On the other hand the movement of
these mandrels has been effected by means of chains and pinions, which are apt to
break or to become encumbered with deposits which clog their movements.
movement has also been obtained by means of wooden connecting rods, which drying
when heated and swelling when damp frequently get out of order, thus rendering
all regular work impossible. The improvements that I have invented have for
their object means of overcoming these various drawbacks and comprise first a
special construction of the apparatus.
This
According to this construction I make the mandrels, moulds, cores or cathodes
preferably of copper with fillings of wood and support them by journals or
trunnions of lignum vitæ turning in glass bearings suitably supported. In order to
move or work the mandrels, moulds, cores or cathodes I employ a set of connecting
rods and cranks made preferably of leaded copper or bronze with copper stays,
bronze journals or trunnions and bearings of cast iron, gun metal or lignum vitæ
with or without fillings of wood for the mandrels. There is preferably one main
connecting rod for moving several mandrels and actuated by one or more cranks on
shafts coupled together by other cranks and a link or connecting rod.
The covering of plumbago or other conducting material used to facilitate the
deposit on the core, mould or cathode has hitherto always been applied either dry
or mixed with oil, grease or similar fatty substance. This method is defective for

page_text: several reasons and gives hardly any security as regards work and manipulation.
According to my invention I replace this method by the following:-
I add to the plumbago sufficient milk to make it liquid and I then spread it on
the mould or core, turning the latter during the operation so as to cbtain as even a
layer as possible, which I rub during the rotation until it has become quite dry.
When the operation is finished I have a mandrel absolutely dry, shining and
perfectly protected from acids. When the mandrel cannot be revolved the covering
is applied by a brush so as to obtain as uniform a layer as possible. This method
of procedure not only has the advantage of rendering the mandrel or core smooth
and shining, but also of preventing any adherence of the deposit to the cathode.
On the other hand I should remark that the solution of metallic salts which
constitute the principal agent for the production of the metals by electrolysis ought,
in order to give the best results, other things being equal, to maintain the same
strength, and to be deprived by decantation or otherwise, of all impurities that they
contain when they have served for an operation of some duration. Amongst the
matters in suspension which are hurtful and which render even the solutions unsuitable
for the work, are some so minute that purification by simple decantation effected by
allowing the liquid to settle even for months, is absolutely insufficient and useless.
Long observation of the work of decantation by simple settling has shown me that
the cisterns, reservoirs or basins which are used for this process and which always
contain a large quantity of liquid, are wrong in their very construction. I have
devised the method of subdividing them into compartments of small depth super-
posed as close as possible one above another, to facilitate the deposit of the matter
in suspension, which does not take place in vessels having a considerable depth. These
compartments can be made of any suitable material, wood, or metal, the metal being in
certain cases able to exert a chemical or oxidizing action on the impurities, thereby
facilitating the oxidation and deposit of the materials. For this purpose any fabric
may be used or india rubber which resists better the action of the acid. Instead of
vessels of great depth and fitted with partitions, I can use flat vessels of any shape
but of slight depth and thereby solve the problem, that is to say a quick and sure
deposit of the matters in suspension. The horizontal subdivisions instead of being
separated one above the other can be disposed in series with winding connections to
allow circulation. Moderate and prolonged heat has a favorable influence on
impure solutions in hastening deposit. I take advantage of this fact by placing in
the decantation reservoirs lead pipes, through which is circulated steam at low
pressure, or very hot water, so as to give a uniform temperature to the liquid, high
or low, according as a deposition more or less rapid is desired, according also as
the solution is more or less impure, and according to the nature of the impurities.
As a rule a temperature of from 40° to 60°, say 50° centigrade, is proper.
pipes may be of any form, straight, curved or serpentine as desired. Also in order
to oxidize certain matters air may be passed into the solution, either by means of a
fan or by stirring up the solution so as to bring it as much as possible into contact
with the air.
The
As regards the working of the metal itself on leaving the electrolytic bath, my
invention consists in giving to the metal thus obtained by electrolysis a cohesion and a
homogeneity much more perfect than that hitherto obtained by transforming it, even
to the interior of its mass, and giving it therefore all the strength it is able to acquire.
I effect this by submitting on their exit from the electrolytic bath tubes or plates
produced by these processes and already beaten, burnished, rolled or not, in the
bath as is done in the Elmore process, to a subsequent drawing, rolling, beating or
hammering sufficient to effect the complete molecular transformation of the metal
and giving to it all the qualities which characterize the metal under treatment.
This application of a physical or mechanical work to a metal which is an
electrolytic production can be combined not only with the Elmore or a like process
but can be employed in all cases where the pieces being of slight thickness are
obtained at a low voltage, without making use of those processes.
My new process has the further advantage of being able to diminish considerably

page_text: the size of the mandrels, cores, moulds &c. necessary to obtain various pieces won
can be manufactured by following simply the Elmore or similar process.
Dated this 13th day of December 1893.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in or relating to Processes and Apparatus for
Obtaining and Depositing Metals by Electrolysis, and in the
Treatment of the Metals after Leaving the Electrolytic Bath.
I, ERNEST STOULS of 16 Rue Drouot, Paris, France, Engineer, do hereby declare
the nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement :-
For some years electrolysis has been employed in the manufacture of metals
for industrial purposes.
The processes as actually worked give good results in the case of gilding,
silvering and electroplating, that is to say when the deposit of metal is of slight
thickness; they are, however, not so satisfactory when it is required to produce a
particular kind of metal, and to obtain, as the Elmore process is particularly adapted
to obtain, a layer of metal thick enough to be afterwards worked and to receive the
various industrial adaptations of which it is capable.
My invention has for its object, various improvements in electrolytic metallurgy,
avoiding the drawbacks at present existing, so that a manufacture is obtained
sufficiently uniform to produce results the homogeneity of which is as perfect as
possible, whatever may be the thickness of the layer of deposited metal.
These improvements, which relate either to different phases of the work itself, or
to the material employed in its execution, have principally for their object,
modifications of the mandrels, moulds, cores or cathodes, of the means of covering
them with plumbago, and of the apparatus for giving them motion; the invention
also relates to methods of purifying the solutions of metallic salts used in the
manufacture, and lastly to additions and modifications as regards the working or
manipulation of the metals on leaving the electrolytic bath.
In the first place the mandrels, moulds and cores whether of iron, steel, copper
or other material bave hitherto been made in a manner absolutely defective. The
mandrels of cast iron have had for example foundations of the same metal or again
fittings of bronze, which in a little time are rendered useless on account of defects
in their construction or because the acids which attack the foundations of these.
mandrels, also deteriorate the liquor. On the other hand, the movement of these
mandrels has been effected by means of chains and pinions, which are apt to break
This move-
or to become encumbered with deposits which clog their movements.
0 ment has also been obtained by means of wooden connecting rods which, drying
when heated and swelling when damp frequently get out of order thus rendering
all regular work impossible. The improvements that I have invented bave for
their object means of overcoming these various drawbacks aud comprise first, a
special construction of the apparatus.
5
According to this construction I make the mandrels, moulds, cores or cathodes
preferably of copper with fillings of wood and support them by journals or trunnions
of lignum vitæ turning in glass bearings suitably supported. In order to move or
work the mandrels moulds, cores or cathodes I employ a set of connecting rods
and cranks made preferably of copper or bronze with copper stays, bronze journals
30 or trunnions and bearings of cast iron, gun metal or lignum vitæ with or without
fillings of wood for the mandrels. There is preferably one main connecting rod or
frame for moving several mandrels and actuated by one or more cranks on shafts
coupled together by other cranks and a link or connecting rod.

page_text: In order to render my invention clear I will now proceed to describe the same
with reference to the annexed drawings.
Figures 1 and 2 represent in elevation and in plan the mechanism I employ for
producing electrolytic deposits on revolving mandrels.
Figures 3, 4, 5 and 6 represent respectively front and side elevations, a section
on the line A B of Figure 3 and a section on the line CD of the same figure, of a
connecting rod or frame for actuating four mandrels.
Figures 7, 8, 9 and 10 represent respectively the same views of a connecting rod
or frame for actuating a single mandrel.
Figures 11, 12, 13 and 14 represent the same views of a connecting rod or frame
for actuating five mandrels, with bearings of lignum vitæ.
Figures 15, 16 and 17 represent in front elevation, end elevation and in section
on the line CD of Figure 16 a copper mandrel with fittings.
In Figures 1, 2, 15 and 17 the drawing is shown broken to indicate that the
mandrel may be of any required length.
The apparatus, shown complete in Figures 1 and 2, comprises one or more
mandrels A A preferably of copper with wood fillings supported on trunnions or
journals B of lignum vitæ turning in glass bearings J which are placed in suitable
supports I. Motion is transmitted to the mandrels by a main connecting rod or
frame C made of copper and which is actuated by one or more cranks D of bronze,
placed at the ends of the shafts M M, coupled together by cranks H H and a
connecting rod G the said shafts M being supported by the bearings E and actuated
by a pulley F driven from any suitable motor. The whole apparatus is mounted
on the beams L of the vats which are stayed by the cross pieces K. In the detailed
views Figures 3 to 10, A represents the body of the connecting rod or frame
preferably of copper. B B are tubular stays made of copper, C are trunnions or
journals of bronze, D the bearings of cast iron or lignum vitæ ; E other tubular
stays of copper; F pins of the same metal. In Figures 11 to 14, A represents the
body of the connecting rod or frame; B B are tubular stays of copper; C other
tubular stays of copper; D lignum vitæ bearings and E pins. In Figures 15 to 17
which represent the mandrel in detail, A represents the copper tube forming the
outside of the mandrel; Ba core or filling of wood; C C are nuts of bronze to
receive bronze screws D with which engage the lignum vitæ trunnions E on which
are fitted the cranks F. G G are washers of caoutchouc forming a watertight
protection to the interior of the mandrel A.
The covering of plumbago or other conducting material used to facilitate the
deposit on the core, mould or cathode has hitherto always been applied either dry,
or mixed with oil grease or similar fatty substance. This method is defective for
several reasons and gives hardly any security as regards work and manipulation.
According to my invention I replace this method by the following:
I add to the plumbago sufficient milk to make it liquid and I then spread it on
the mould or core, turning the latter during the operation so as to obtain as even a
layer as possible, which I rub during the rotation until it has become quite dry.
When the operation is finished I have a mandrel absolutely dry, shining and
perfectly protected from acids. When the mandrel cannot be revolved, the
covering is applied by a brush so as to obtain as uniform a layer as possible. This
method of procedure not only has the advantage of rendering the mandrel or core
smooth and shining but also of preventing any adherence of the deposit to the
cathode. On the other hand I should remark that the solutions of metallic salts
which constitute the principal agent for the production of the metals by electro-
lysis ought in order to give the best results, other things being equal, to maintain
the same strength, and to be deprived by decantation or otherwise of all impurities
that they contain when they have been some time in operation. Amongst the
matters in suspension, which are hurtful, and which render even the solutions
unsuitable for the work are some so minute, that purification by simple decantation
effected by allowing the liquid to settle even for months is absolutely insufficient
and useless. Long observation of the work of decantation by simple settling has

page_text: a con--
shown me that the cisterns, reservoirs or basins which are used for this process and'
which always contain a large quantity of liquid, are wrong in their very con-
struction. I have devised the method of subdividing them into compartments of
small depth placed as close as possible one above another to facilitate the deposit.
of the matter in suspension which does not take place in vessels having
siderable depth. These compartments can be made of any suitable material, wood
or metal for example, the metal being in certain cases able to exert a chemical or
oxidising action on the impurities thereby facilitating the oxidation and deposit of
the materials. Or any suitable fabric may be used, or india-rubber which resists.
better the action of the acid.
Instead of vessels of great depth and fitted with partitions, I can use flat vessels.
of any shape but of slight depth and thereby solve the problem, that is to say a
quick and sure deposit of the matters in suspension. The horizontal subdivisions
instead of being separated from each other can be disposed in series with winding
communications to allow circulation.
Moderate and prolonged heat has a favorable influence on impure solutions in
hasteuing deposit. I take advantage of this fact by placing in the decantation
reservoirs lead pipes, through which is circulated steam at low pressure, or very
hot water, so as to give a uniform temperature to the liquid, high or low according
as a deposition more or less rapid is desired, according also as the solution is more
or less impure and according to the nature of the impurities. As a rule a
temperature of from 40° to 60° say 50° centigrade is proper. The pipes may be
of any form, straight, curved or serpentine as desired.
Also in order to oxidize certain matters and to render the temperature uniform,.
air may be passed into the solution, either by means of a fan or by stirring
up the solution so as to bring it as much as possible into contact with the air.
As regards the working of the metal itself on leaving the electrolytic bath, my
invention consists in giving to the metal thus obtained by electrolysis a cohesion.
and a homogeneity much more perfect than that hitherto obtained by transforming
it, even to the interior of its mass, and giving it therefore all the strength it is able
to acquire. effect this by submitting on their exit from the electrolytic bath
tubes or plates produced by these processes and already beaten, burnished, rolled
or not, in the bath as is done in the Elmore process, to a subsequent drawing,
rolling, beating or hammering sufficient to effect the complete molecular trans-
formation of the metal and give it to all the qualities which characterize the metal
under treatment. This application of a physical or mechanical work to a metal
which has been produced by electrolysis can be combined not only with the
Elmore or a like process but can be employed in all cases where the pieces being
of slight thickness, are obtained at a low voltage, without making use of those
processes.
My new process has the further advantage that it allows of considerably
diminishing the size of the mandrels, cores, moulds &c. necessary to obtain
various pieces which can be manufactured by following simply the Elmore or
similar process.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. Constructing mandrels, moulds, cores or cathodes for electrolytical purposes
of copper with fillings of wood and supported on lignum vitæ trunnions or journals
mounted in glass bearings, substantially as herein before described and shown in
the accompanying drawings.
2. For the purpose of rotating the mandrels, moulds, cores or cathodes, a set of
cranks and connecting rods or frames made of bronze or copper, with tubular
stays of copper, trunnions or journals of bronze and bearings of cast iron or
lignum vitæ, the mandrels being with or without fillings or cores of wood,.
substantially as herein before described and shown in the accompanying drawings.

page_text: 3. Coating the mandrels, moulds, cores or cathodes employed for the electro-
deposition of metals with plumbago mixed with milk, substantially as and for the
purpose herein before described.
4. For the purifying of solutions of metallic salts employed in the electro-
deposition of metals, the employment of relatively large surfaces upon which the
deposit of materials in suspension takes place such large surfaces being obtained
either by having partitions or subdivisions in the basin or receptacle with or without
winding communications between them, or by using shallow basins, substantially
as herein before described.
5. In the purifying, by deposit of their impurities, of solutions of metallic salts
employed in the electro-deposition of metals, the employment of means whereby the
temperature of the solution can be maintained at about 40° to 60° centigrade and
hereinbefore
whereby air can be passed into the solution, substantially as
described.
6. The combination with the Elmore process or analogous process of obtaining
metals by electrolysis of a subsequent treatment of the deposited metal by drawing,
rolling, hammering or the like, substantially as described, in order to effect a mole-
cular change of the deposited metal and to impart to it all the qualities which
characterize the metal that is under treatment.
7. In the case of electro-deposition with low voltage, the subsequent treatment
of the deposited metal by rolling, hammering, drawing or the like, substantially as
described, in order to effect molecular change of the deposited metal and to
impart to it all the qualities which characterize the metal that is under treatment.
Dated this 1st day of August 1894.
J. C. MEWBURN & ELLIS,
55 & 56, Chancery Lane, London, Patent Agents.