IMPROVEMENTS IN MOULDS FOR ELECTRO- METALLURGY
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWPER, of No. 20, Southampton Buildings, Chancery Lane, in the County of
Middlesex, Patent Agent, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Seventeenth day of
February (One thousand eight hundred and fifty-one), in the fourteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Charles Cooper, my exors, admors, and assigns, Her especial licence, full
power, sole privilege and authority that I, the said Charles Cowper, my exors,
admors, and assigns, or such others as I, the said Charles Cowper, my exors,
admors, or assigns, should at any time agree with, and no others, from time
time and at all times during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within England, Wales, and
the Town of Berwick-upon-Tweed, and in the Islands of Guernsey, Jersey,
Alderney, Sark, and Man, and also in all Her Majesty's Colonies and Plan-
tations abroad, the Invention of "IMPROVEMENTS IN MOULDS FOR ELECTRO-
METALLURGY," (communicated to me from a certain foreigner residing abroad);
in which said Letters Patent is contained a proviso that I, the said Charles
Cowper, shall cause a particular description of the nature of the said Inven-
tion, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, to be inrolled in Her Majesty's High

page_text: Court of Chancery within six calendar months next and immediately after the
date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Cowper, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed are fully described and
ascertained in and by the following statement thereof, that is to say :-
The Invention consists in an improved mode or modes of forming moulds of
elastic or glutinous substances, and rendering them better conductors of elec-
tricity by introducing good conducting materials in the process of forming the
moulds.
The substances employed to form the moulds are gelatine or glue, gutta
percha, caoutchouc, or other similar elastic or glutinous substance.
The mode of operating with gelatine or glue is to place the model, after
oiling its surface, in a case or box, and to cover the surface of the model
wholly or partially with a number of fine wires, strips or pieces of metal, the
ends of which are allowed to project. The case is then filled with the melted
gelatine or glue, and allowed to remain until the gelatine has become cool and
solid. The model is then removed, and a gelatine mould is thus obtained,
with a number of fine wires imbedded in the surface, which has been in con-
tact with the model, and which is an exact counterpart of the model. This
surface is then covered with bronze powder or other metallic powder, leaf, or
film, or with plumbago, or other conducting substance, and the remainder of
the mould is covered with varnish or grease, or other similar substance, to
protect it from the action of the solution into which it is to be immersed..
The projecting ends of the wires are now connected to one pole of voltaic
battery, magneto-electrical machine, or other source of electricity, and the
mould is immersed in the depositing vat containing a metallic solution, and a
piece of metal attached to the other pole of the voltaic battery or other source
of electricity; or the mould may be connected at once to a piece of zinc, and
placed in the apparatus known to electro-metallurgists as the single cell appa-
ratus. The electricity being distributed over the surface of the mould by the
fine 'metallic wires, has in no case to be conducted more than a very short
distance by the bronze powder or black lead, and the consequence is that the
deposit commences simultaneously at all parts of the surface, which is thus
rapidly and equally covered before the gelatine can be attacked by the solution.
If, on the contrary, the coating of bronze powder or plumbago were employed
alone to conduct the electricity over the surface of the mould without the aid
of the fine metallic wires, it would be difficult or impossible to insure the

page_text: complete covering of the mould by the deposit, especially when the solution is
of a nature to act rapidly on the gelatine. After a sufficient thickness of
deposit has been obtained, the mould is removed from the vat, and separated
from the deposit either by pulling it off or by melting or dissolving it off. In
the first case the mould may sometimes be preserved and used over again.
In operating with gutta percha it is first softened by heat, and it is advanta-
geous to mix it with about one-fifth part of its weight of naptha, coal oil, or
other oil or solvent, for the purpose of rendering it more plastic and flexible.
It is then spread out on a piece of glass or other smooth surface, so as to form
a sheet of about half an inch thick, more or less, according to the size and
form of the object to be moulded. The surface of the model is covered with
fine metallic wires, as already described with regard to the gelatine moulds, and
the whole is then covered with a sheet of the gutta percha prepared as above
mentioned. The whole is placed in a warm chamber or stove until the gutta
percha softens, and it is then taken out, the gutta percha pressed in contact
with the model, and allowed to cool. When cold the model is removed, and
the mould in which the fine metallic wires are imbedded is covered with
bronze powder or plumbago, or other conducting substance, and connected by
means of the fine wires to the pole of the voltaic battery or other source of elec-
tricity. It is then introduced into the depositing vat, as already described.
If the solution in the vat is capable of acting on the gutta percha, the part of
the mould which is not covered with the conducting coating is protected by
varnish, grease, or some other substance insoluble in such solution. Caout-
chouc is softened by the addition of naptha, bisulphuret of carbon, or other
solvent, and treated in a similar manner to the gutta percha; or it may be
applied to the model in the state of a thick solution, laying on several coats,
and allowing each to dry before adding another, until a sufficient thickness of
mould is obtained. Gutta percha may also be similarly applied in a state of
solution. Gutta percha and caoutchouc are more particularly applicable to
metallic models, although they may be used with other descriptions of models;
and in like manner the gelatine or glue is applicable to metallic and other
models, and will in most cases be found preferable to the other substances.
It may be used alone or mixed with sugar or treacle, a small quantity of
which retards its drying and hardening.
Having now described the nature of the Invention, and in what manner the
same is to be performed, I wish it to be understood that what I claim is, the
forming mould for electro-metallurgy by covering the model with metallic
wires, strips, or pieces, and applying the gelatine or other elastic or glutinous
material to form the mould in such manner that the wires or other metallic

page_text: substances may remain imbedded in its surface, and be adapted for conducting
the electric current to the surface of the mould, as herein-before described.
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this Fifteenth day of August, in the year of our Lord
One thousand eight hundred and fifty-one.
Enrolled the Sixteenth day of August, in the year of our Lord One
thousand eight hundred and fifty-one.