Manufacture of Compound Wire of Steel and Silver.
Year: 1898

page_text: Date of Application, 22nd Jan., 1898-Accepted, 7th Jan., 1899
COMPLETE SPECIFICATION.
Manufacture of Compound Wire of Steel and Silver.
I, EDOUARD MARTIN, of 46, Rue de Dunkerque, Paris, France, Operative, 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:-
My invention relates to a manufacture of compound wire having a steel core
and an outer coating of silver, the two metals being intimately combined with each
other so as practically to form a solid compound metal wire. For this purpose I
proceed as follows:-
I take a bar of steel of any desired dimensions, but preferably of from 40 to
50 milimetres diameter and about 80 centimetres in length. This bar is in the
first instance turned in a lathe in order to obtain a very perfect metallic surface,
and it is formed with the one end rounded and the other end pointed, as indicated
at. Fig. 1 on the accompanying drawing. These bars are then carefully pickled,
after which I produce by electrolytic deposit, a thin coating of copper thereon, as
indicated at the cross section at Fig. 2. I may also deposit by the same means a
thin coating of zinc or tin, this being deposited either before or after the copper
coating. then place the bars in a bath of water and the operative rubs them
energetically with a compound of cyanide of silver and cream of tartar.
By this means the copper becomes slightly silvered.
The bars are then washed, cleansed and dried.
I prepare sheets or foils of silver of 1000 fine, or of silver alloy, about 1/4th of a
milimetre thick, and about 9 centimetres wide.
I cut these foils of the same length as the bars, namely 80 c.m. and as their
width would not be sufficient to envelope the bar and maintain it rolled round the
same, I take five or six such strips of silver foil placed side by side in such manner
as to overlap each other by about one half of their width, as shewn in the cross
section and plan at Figs. 3 and 4, so as to produce an envelope sufficiently wide
for wrapping two or three times round the bar. This envelope being laid upon a
table covered with cloth, I place the bar thereon, and roll it up therein, so as to
form a covering as shewn in the cross section at Fig. 5.
By this means I provide the bar with the desired amount of silver in proportion
to the weight of the bar, which proportion may vary from 5 to 100 grammes of silver
per kilogramme of steel. When the bar has been thus enveloped in the
silver covering, I wind a hempen band of about 20 c.m. width helically round the
silver covered bar, as indicated at Fig. 6, this covering having for its object to
prevent the heat to which the bar is afterwards subjected from causing the separa-
tion of the silver therefrom.
I then place the covered bars in a heating apparatus, such as is shewn in vertical
section at Fig. 7, consisting of a number of iron tubes T of about 100 milimetres
diameter and 90 c.m. long, supported over a fire grate, and serving to receive the
bars B prepared as above described.
Supports ss for the bars are provided within the tubes so as to maintain the
bars out of direct contact therewith.