Improvements in and connected with Carbon Electrode 'Connections.
Year: 1893

page_text: Date of Application, 1st Nov., 1893
Complete Specification Left, 26th July, 1894-Accepted, 22nd Sept.,
1894
PROVISIONAL SPECIFICATION.
Improvements in and connected with Carbon Electrode
'Connections.
HARRY THEODORE BARNETT, Mem. Inst. Elec. Engrs. 14 Narcissus Road West
Hampstead London N.W. do hereby declare the nature of this invention to be as
follows:-
This invention is for the purpose of providing a convenient connection for carbon
electrodes used in electric batteries or for electrolysis.
I cause the carbon to be manufactured or subsequently provided with a hole or
recess in some portion of its bulk and in this recess I cause a portion of the so-called
"connection" to rest, and I retain the same in position and in contact with the
carbon by a wedge or plug.
I prefer the carbon to be tubular, and to use for the connection a wire or strip of
electric conductor incorrodible in the solution and under the conditions which the
electrode will have to bear.
No preparation of the carbon or protection of the connection is necessary when
the incorrodible metals are used for connection.
It is desired frequently to construct larger electrodes than could be obtained in
tubular form; therefore it becomes necessary to combine a number of small ones
together, joining them electrically by their incorrodible connections to a connection-
conductor common to all: for this purpose an incorrodible metal may be used, but
in comparison with the small portions in direct contact with the carbon, the expense
entailed would be very considerable. I have therefore devised the following
make-up, which is satisfactory and inexpensive
I take a lead-covered or otherwise protected wire of copper or other corrodible
metal and having stripped away its protecting covering for a distance barely
sufficient to allow of its attachment, it is then permanently connected to all the
incorrodible connections attached to the several carbons, by soldering, brazing or
some other suitable process, preferably before, but possibly after being connected
together in the manner just mentioned, the connection-bearing ends of the carbons
are placed through close-fitting holes in the lower portion of an annular, round,
square or other shaped tray of suitable material, the edges of which are sufficiently
high to stand above the connection joints-the said joints having been made, the
tray is filled with sulphur, battery cement, pitch or other suitable protecting
material so as to cover the whole joint and reach up to and over the edge of the
protecting covering upon the wire of corrodible metal.
Dated this 28th day of October 1893.
COMPLETE SPECIFICATION.
Improvements in and connected with Oarbon Electrode
Connections.
HARRY THEODORE BARNETT M.I.E.E. 14 Narcissus Road West Hampstead, 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 aud by the following
statement :-
This invention is for the purpose of providing a convenient connection for carbon
electrodes as used in electric batteries or for electrolysis.

page_text: I cause the carbon to be manufactured or subsequently provided with a hole or
recess in some portion of its bulk & in this recess I cause a portion of the so called
" connection to rest & 1 retain the same in position & in contact with the carbon
by a wedge or plug.
"
The connection may be a copper wire, the carbon may be of the "Leclanché
type such as is sometimes capped with lead, & the wedge or plug may be of oak or
teak wood, obonite, celluloid, vulcanised fibre, or other suitable material-the
carbon top having been treated with paraffin or ozokerit wax the end of the wire
connection may be placed through one of the holes in the carbon top & bent round
to ensure its remaining in position & then permanently retained by lightly driving
a plug or wedge of suitable shape through the unoccupied portion of the orifice in
which the wire connection is placed. To protect the whole joint from injury or
corrosion the whole carbon top & connection may be dipped in some suitable
protecting cement or substance."
I prefer the carbou to be tubular & to use for the connection a wire or strip of
some electricity conductor incorrodible in the solution & under the conditions which
the electrodes will have to bear. The carbon. tubes may conveniently be hollow
electric are light rods such as are made for coring but with the core omitted. For
general purposes the incorrodible connection may conveniently be of silver but if
the electrode is to be used in nitric or mixed acids platinum is preferable-no
preparation of the carbon or protection of the connection is necessary when the
incorrodible metals are used for connection.
It is frequently desired to construct larger electrodes than could be obtained in
tubular form therefore it becomes necessary to combine a number of small ones
together joining them electrically by their incorrodible connections to a connection
conductor common to all-for this purpose an incorrodible metal may be used but
in comparison with the small portions in direct contact with the carbon the expense
entailed would be very considerable-I have therefore devised the following
make up which is satisfactory & inexpensive. 1 take a lead covered or otherwise
protected wire of copper or other corrodible metal & having stripped away its
protecting covering for a distance barely sufficient to allow of its attachment it is
then permanently connected to all the incorrodible counections attached to the
several carbous by soldering, brazing or some other suitable process. Before or
after being connected together in the manner just mentioned the connection
bearing ends of the carbons are placed through close fitting holes in the lower
portion of an annular, round, square or other shaped tray of suitable material
the edges of which are sufficiently high to stand above the connection joints-the
said joints having been made the tray is filled with sulphur, battery cement, pitch
or other suitable protecting material so as to cover the whole joint & reach
up to & over the edge of the protecting covering upon the wire of corrodible
metal.
Turned wood forms a good circular tray, tenk may be used & it is convenient to
indurate it with wax or to enamel. it.
A good mixture for filling the tray with consists of 1 part of resin, 1 of shellac,
2 parts of paraffin wax, 4 parts of ozokerit, & 8 parts of pitch.
Having now particularly ascertained & described the nature of my said inven-
tion & the manner after which it may be performed I declare that what I
claim is
Claim I. The combination of a recessed carbon electrode in an electric battery
or electrolytic element, with an electric connection some portion of which is within
the said recess, & a wedge or plug also situated within the same recess & maintaining
the said connection carbon electrode in good mechanical & electrical contact,
substantially as described.
Claim II. The combination of a tubular carbon in an electric battery or
electrolytic element, with an incorrodible connection entering the interior of the
said tubular carbon, & a wedge or plug holding the said incorrodible conductor

page_text: within, against & in electrical contact with the said tubular carbon, substantially as
described.
Claim III. The combination of two or more tubular carbons in an electric
battery or electrolytio element, provided with wedge or plug attached incorrodible
connections, with a vessel provided in the lower portion with holes through which
rise the connection bearing ends of the said carbons & a corrodible electricity
conductor covered in its unattached' portion with some protecting substance,
attached & common to all the incorrodible connections, together with a sufficient
quantity of cement or other protecting substance in the said cup or dish to cover
& protect the uncovered portion of the said corrodible conductor, substantially as
described.
Dated this 26th day of July 1894.