Improvements in Conducting Contacts with Carbon or other Non-metallic Electrodes.
Year: 1896

page_text: Date of Application, 4th July, 1896-Accepted, 5th Sept., 1896
COMPLETE SPECIFICATION.
Improvements in Conducting Contacts with Carbon or other
Non-metallic Electrodes.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of London, Electrical Engineers, and Dr. EUGEN
FERDINAND AUGUST ОBACH, of 2 Victoria Road, Old Charlton, in the County
of Kent, Chemist, do hereby declare the nature of this invention and in what
mauner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
This invention relates to means of making certain and durable conducting
contacts with carbon or other non-metallic electrodes, as we shall describe referring
to the accompanying drawings.
Fig. 1 is an elevation and Fig. 2 is a sectional plan of a contact according to our
invention of saddle form;
Fig. 3 is an elevation and Fig. 4 is a plan of a contact in cap form.
Fig. 5 is a sectional plan of a multiple contact.
Referring first to Figs. 1 and 2, S is a saddle of lead or other metal cast on the
carbon or other non-metallic electrode C.. According to our invention, we drill a
hole through the sides of the saddle and the electrode; in the hole of the electrode
we put a lining P of thin sheet platinum; we then cast into the hole a plug M of
metal which expands in setting, so that the platinum lining of the hole becomes
closely pressed against the plug M inside and against the material of the electrode C
outside. The platinum is preferably tinned on the inside so that it becomes
soldered to the plug M.
The hole may be a little countersunk as shewn.
For the metal of the plug various alloys may be used; we find a good
composition to be 2 parts by weight of bismuth, 2 parts of lead and 1 part of tin.
Referring to Figs. and 4, in which parts corresponding to those in Figs. 1
and 2 are marked by similar reference letters, the cap S is cast on the electrode
and connected to it by two plugs M cast in holes having platinum linings P.
As shewn in Fig. 5 B is a bar of copper or other good conducting metal in which
are rivetted a number of projecting studs A. Through the electrode C holes are
bored corresponding in number and position with the studs A but of larger diameter,
and the alloy is cast in these holes so as to embrace the studs which are preferably
tinned in the first instance, so that the alloy becomes soldered to them. The holes
of the electrode in Fig. 5 are lined with piatinum, preferably tinned, as described
with reference to the other figures.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. A conducting contact of a metallic saddle or cap with a carbon or other.
non-metallic electrode made by casting the saddle or cap on the electrode, boring
a hole through the whole, lining the hole of the electrode with platinum and
casting in the hole a plug of alloy that expands in setting, substantially as
described.
2. A multiple conducting contact of a metallic bar with a carbon or other
non-metallic electrode by inserting studs projecting from the bar into holes of

page_text: larger diameter in the electrode, lining these holes with platinum, and casting into
these holes plugs of alloy that expand in setting, substantially as described.
Dated this 4th day of July 1896.
ABEL & IMRAY,
Agents for the Applicants.