Improvements in and connected with the Manufacture of Electric Conductors, for Use as Leading-in Wires or Strips in the Manufacture of Incandescent Electric Lamps, Vacuum Tubes, and the like.
Year: 1896

page_text: Date of Application, 13th Jan., 1896
Complete Specification Left, 13th Oct., 1896-Accepted, 24th Dec., 1896
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Manufacture of Electric
Conductors, for Use as Leading-in Wires or Strips in the
Manufacture of Incandescent Electric Lamps, Vacuum Tubes,
and the like.
SHERARD OSBORN COWPER-COLES Metallurgical Engineer of 16 Adam Street
Manchester Square in the County of Middlesex, do hereby declare the nature of
this invention to be as follows:-
The object of this invention is to produce metallic conductors suitable for electric
conduction in incandescent lamps and vacuum tubes. For this purpose I employ
pure iron plated with an alloy having a low melting point; for example an alloy
containing tin, lead, cadmium and aluminium.
In carrying out my invention for the production of leading in wires for
incandescent lamps, I take a length of chemically pure iron preferably refined by
electrolysis and carefully clean it by chemical or mechanical means to remove all
traces of oxidation therefrom, the wire thus prepared is then passed through a bath
containing a inolten alloy, I have obtained good results with an alloy composed of
tin 50 parts, lead 25, cadmium 25 to insure a perfect coating I find it advantageous
to cover the surface of the molten alloy with zinc chloride or other suitable flux.
Dated this 10th day January 1896.
SHERARD COWPER-COLES.
Improvements in and connected with the Manufacture of Electric
Conductors, for Use as Leading-in Wires or Strips in the
Manufacture of Incandescent Electric Lamps, Vacuum Tubes,
and the like.
I, SHERARD OSBORN COWPER-COLES Metallurgical Engineer, late of 16 Adam
Street, Manchester Square in the County of Middlesex, now of 39 Victoria Street,
in the City of Westminster, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
The object of this invention is to produce metallic conductors suitable for use as
leading-in wires or strips in the manufacture of incandescent electric lamps, vacuum
tubes and the like, in substitution for the platinum wires hitherto used for the
purpose. Attempts have been made to employ iron wire for this purpose and
it has been proposed to coat such wires with another metal such as tin, but these
attempts have hitherto failed. I have discovered that it is necessary, to secure
successful results, to employ pure iron or iron which is practically pure and that
D

page_text: ordinary commercial iron is not suitable for the purpose. I have also discovered
that it is necessary to coat or cover the iron conductors with an alloy not readily
oxidizable and of a low melting point such that it will become fused when the heat
necessary for effecting the sealing-in of the conductors is applied and it should be
coated with a vitreous coating prior to the sealing-in process. According to my
invention I employ preferably chemically pure iron produced by electrolysis, which
may be done by employing scrap iron as an anode with a cathode of aluminium or
other metal from which deposited iron can be readily removed and any suitable
electrolyte such as a solution of iron sulphate or sulphuric acid or the like. The
electrolytically deposited iron is stripped from the cathode and formed into the
necessary shape to constitute the required wires or strips. All traces of oxidation
or impurity should then be removed therefrom, and the wires or strips thus
prepared be passed through a bath containing the molten alloy. I have obtained
good results with an alloy composed of 50 parts (by weight) of tin, 25 parts of lead,
and 25 parts of cadmium but I do not limit myself to this particular alloy-as
various proportions of tin and lead may be used with or without various proportions
of the other metals employed. To ensure a perfect coating I find it advantageous
to cover the surface of the bath of molten alloy with zinc chloride or other
suitable flux.
In applying the wires or strips to the lamps, tubes or the like a thin coating of
glass is preferably applied (by spinning or wrapping for example) to the parts of
the wires or strips which are to be sealed into the bulb, tube, or the like, the
sealing-in of the wires, or strips, is then effected by the application of heat in the
ordinary way, when owing to the iron employed being in a pure or practically pure
state and the alloy covering it being of the requisite low melting point the wires or
strips become hermetically attached to the glass of the bulb, tube, or the like,
through which they pass.
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. Leading-in wires or conductors for incandescent electric lamps, vacuum tubes,
and the like, made of pure or practically pure iron covered with an alloy of low
melting point, as hereinbefore explained.
2. Leading-in wires or conductors for incandescent electric lamps, vacuum tubes,
and the like, made by electro-depositing iron, forming wires or strips therefrom,
and then covering them with an alloy of low melting point, as hereinbefore
explained.
Dated this 13th dor of October 1806
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.