Improved Means to be Employed in the Production of Sheets, or Strips, or other Form of Metal by Electro-deposition.
Year: 1895

page_text: Date of Application, 24th Oct., 1895
Complete Specification Left, 21st July, 1896-Accepted, 5th Sept., 1896
Improved Means to be Employed in the Production of Sheets, or
Strips, or other Form of Metal by Electro-deposition.
I SHERARD OSBORN COWPER-COLES, of 16 Adam Street, in the County of
London, Engineer, do hereby declare the nature of my invention to be as
follows:-
:-
The object of my invention is to provide means for obtaining metal in the form
of sheets, or strips, or other equivalent forms, by electro-deposition, where it is
required that the metal sheet, or the like, to be obtained, shall be entirely made by
electro-deposition, as distinguished from an article consisting of a permanent basis,
or backing, covered with an adherent coating of metal effected by electro-
deposition.
It is necessary, in producing sheets, or other metal forms, consisting entirely of
electro-deposited metal, to provide a cathode, or base, upon which the metal is.
deposited but from which the deposited metal can be afterwards readily removed..
It has hitherto been necessary to provide a cathode for this purpose which is
covered by a greasy, or fatty, matter, such, for example, as wax dissolved in
benzene; but it has been found, in practice, that it is impossible to ensure such a
coating as shall be so perfect as to prevent the adherence of the deposited metal
to the cathode in places, which, however minute, will prevent the subsequent
removal of the deposited metal in a perfect form from the cathode.
I have, by trial and experiment, found that a cathode formed of aluminium, or
an alloy, or compound, containing aluminium, will receive an electro-deposition of
metal, and that the metal so deposited can afterwards be readily separated from
the said cathode without injury to its form. This is owing, I believe, to the
formation of a thin, and even, coating of oxide on the cathode made as described,.
which, whilst not interfering with the electro-deposition of the metal thereon,
prevents such adherence of the deposited metal to the cathode, as will interfere
with the removal, in perfect form, of the deposited metal from the cathode.
Dated this 24th day of October 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
Improved Means to be Employed in the Production of Sheets, or
Strips, or other Form of Metal by Electro-deposition.
I SHERARD OSBORN COWPER-COLES late of 16 Adam Street in the County
of London now of No. 39 Victoria Street in the City of Westminster in England
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 :-
The object of my invention is to provide means for obtaining metal in the form.
of sheets or strips, or other forms, by electro deposition where it is required that
D

page_text: the metal sheet, or other form of metal to be obtained, shall be entirely made by
electro-deposition, as distinguished from an article consisting of a permanent basis,
or backing, covered with an adherent coating of metal effected by electro-
deposition.
It is necessary in producing sheets, or other metal forms, consisting entirely of
electro-deposited metal, to provide a cathode, or base, upon which the metal is
deposited but from which the deposited metal can be afterwards readily removed.
It has hitherto been necessary to provide a cathode for this purpose which is
covered by a greasy, or fatty, matter, such, for example, as wax dissolved in
benzene, but it has been found, in practice, that it is impossible to ensure such a
coating as shall be so perfect as to prevent the adherence of the deposited metal
to the cathode in places which, however minute, will prevent the subsequent
removal from the cathode of the deposited metal in a perfect form.
i
I have, by trial, and experiment, found that a cathode formed of aluminium, or
an alloy, or compound containing a large percentage of aluminium, will receive an
electro-deposition of metal, and that the metal so deposited can afterwards be
readily separated from the said cathode for example, I may remove it by rubbing
it therefrom or by stripping it in the form of sheets. I prefer the former plan for
the removal of deposited gold.
The non-adherence, of the deposited metal is owing I believe, to the formation
of a thin and even loose coating of oxide on the described cathode, which whilst
not interfering with the electro-deposition of the metal thereon prevents such
adherence of the deposited metal to the cathode as will interfere with the removal,
in perfect form, of the deposited metal from the cathode. If an aluminium alloy
be used I find that, to give good results the amount of aluminium should not be
less than about 50 per cent. of the alloy. The invention can be applied to the
deposition of various metals such for example as gold, zinc, and iron. The
cathodes may be made of any suitable form such as plates or continuous bands
traversed through the electrolyte or of drums revolving therein.
Gold electro-deposited upon an aluminium cathode from cyanide, or other
solutions, can be readily removed in the form of gold leaf.
The deposited metal is preferably removed from the cathode whilst it is wet.
If allowed to dry before the removal is effected it should be immersed in a weak
alkaline or acid solution before removal is proceeded with.
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 :-
:-
In the obtainment by electro-deposition of metal in the form of sheets, or
strips, or other form, the employment for the electric current passed through a
solution of the metal to be deposited, of a cathode made of aluminium, or of an
alloy of aluminium, as hereinbefore described.
Dated this 21st day of Julv 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.