Year: 1887

page_text: Date of Application, 31st Mar., .1887
Complete Left, 2nd Dec., 1887
Complete Accepted, 29th Mar.,
1888
I HENRY LIEPMANN Ph. D. and F.C.S. Managing Director of the Liepmann Carbon
Company Limited of Nelson Wharf, Millwall, in the County of Middlesex do hereby
declare the nature of this invention to be as follows:-
According to this invention I construct compound carbon "platos" or electrodes
by casting around carbon rods a lead setting or head all as hereinafter described.
For the purpose of my invention I employ a mould which may suitably be of
wrought or cast iron and which is formed with a straight or annular recess (according
as I want to make a flat "plate" or annular electrode) into which mould the bottom
ends of a number of the carbon rods are inserted with small intermediate intervals
and the inner sides of the mould are by preference of a corrugated form, that is to
say, the recess is on each side narrowed in between each two carbons. The carbon
rods are by preference provided with notches before being inserted each in its place.
Lead is then run in which fills the spaces between the carbons themselves and between
the carbons and the interior of the mould, so that the lower ends of the carbons become
enclosed in the lead and are firmly held thereby, especially if previously provided
with notches. The carbons are thus also in good electrical contact with the lead. In
constructing flat "plates" by this method I strengthen them and prevent buckling or
bending by inserting thin sheet bands of brass or other suitable metal into the lead
in the mould while the lead is still in a molten state. These metallic strengthening
bands follow the configuration of the interior of the mould and are carefully coated
with lead before insertion. When the "plate or ring thus formed has been taken
out of the mould I place the same in a bath of molten or dissolved paraffin reaching
just above the lead setting or if desired to a greater or the whole depth of the carbon
rods in order to prevent the liquids with which the carbons have to come in contact
I DO027
"

page_text: from penetrating into the interior of the carbons. I do not confine myself to the use
of molten or dissolved paraffin for this purpose, as it may be desirable in some
instances to replace the paraffin by other bodies or mixture of bodies such as those of
the classes to which paraffin or ozokerit, stearic acid, beeswax, Japanese wax and
such like, rosins, gutta percha, India rubber either molten or dissolved, belong. I
then cover the lead setting or head and the parts of the carbon rods adjoining same
with insulating material. For very deep or long carbon rods I provide a setting at
the bottom of the plate as well as at the top or head and this setting may be of the
same kind as the one described for the top, or it may be only insulating material
alone or the rods may first be tied together with lead wire for giving additional
support to the insulating material; or I may use a wood frame which may be soaked
in paraffin, or I use any other suitable support at this place.

page_text: " Plates" or Electrodes for Use in Primary Batteries, and
for Electro-metallurgical, Electrolytical, and other Electrical
Purposes.
I, HENRY LIEPMANN Ph. D. and F.C.S. Managing Director of the Liepmann
Carbon Company Limited of Nelson Wharf Millwall in the County of Middlesex
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 :-
According to this invention I construct compound carbon "plates" or electrodes
of very extended active surface exposed to the exciting liquid by casting around one
or both ends of carbon rods a lead setting or head all as hereinafter described. For
the purpose of my invention I employ a mould which may suitably be of wrought or
cast iron and which is formed with a straight or annular recess (according
as I want to make a flat plate or annular electrode) into which mould the
bottom ends of a number the carbon rods are inserted with small intermediate
intervals and the inner sides of the mould are by preference of a corrugated
form that is to say the recess is on each side narrowed in between each two carbons.
Figure 1 is a plan view and Figure 2 a vertical cross section on line - of a
mould for producing a setting of lead or other suitable metal or alloy for a number of
carbons arranged side by side so as to form a flat compound plate with interstices of
sufficient width for the exciting liquid to pass between.
Figure 3 is a plan view and Figure 4 à vertical section on line.y-y Figure 3 of a
mould for producing a similar setting for a number of carbons arranged in a circular
row so as to form an annular plate or electrode.
The two inner sides a a of the recess may be of a corrugated form as shown or they
may be plain or straight. The carbon rods are by preference provided with notches
before being inserted each in its place for the purpose of affording a firmer hold of
the lead on the carbons. For the sake of convenience I may hold the carbon rods
temporarily in a frame at one end. while the other ends of the carbons are inserted in
the recess a a of the mould. (This frame is removed when the lead has set.) Lead
is then run in which fills the spaces between the carbons themselves and between the
carbons and the interior of the mould so that the lower ends of the carbons become
enclosed in tho. lead and are firmly held thereby especially if previously provided
with notches as shewn. The carbons are thus also in good electrical contact with
the lead.
In constructing "plates" by this method I strengthen them and prevent buckling
or bending by inserting thin sheet bands of brass or other suitable metal into the lead
in the mould while the lead is still in the molten state, or before the lead is run in.

page_text: The circles c show the carbon rods, and the wave lines d show the brass bands or
strips. These metallic strengthening bands d may generally follow the configuration
of the interior of the mould being either of a wavy or zig zag or corrugated form as
shown, or straight. They are carefully coated with lead before insertion.
a
When the flat or annular "plate" or ring thus formed has been taken out of the
mould I place the same with the lead setting downward in a bath of molten or
.dissolved paraffin reaching just above the lead setting or if desired to
greater depth or the whole depth of the carbon rods in order to prevent the liquid
with which the carbons have to come in contact from penetrating into the interior of
the carbons.
The paraffin is caused to penetrate into the interior, but the outer surface of the
carbons should be clean, and any paraffin that may be left on the outside should be
removed mechanically or by a solvent. I do not confine myself to the use of molten
or dissolved paraffin wax for this purpose as it may be desirable in some instances to
replace the paraffin by other bodies or mixture of bodies such as those of the classes
to which paraffin or ozokerit, stearic acid, beeswax, Japanese wax and the like, resins,.
gutta percha, India rubber either molten or dissolved belong.
I then cover the lead setting or head and the parts of the carbon rods immediately
adjoining same with insulating material which may also serve to fasten the binding
screw. As a suitable insulating material I may mention that known as "megohmite
and used by the Liepmann's Carbon Company Limited.
In Figures 5 to 16 I have shown some forms of carbon plates made according to
my invention.
Figure 5 is a front view and Figure 6 a vertical cross section of a flat plate thus
made. The carbons c are at their upper ends held in the cast lead setting produced
by means of the mould. Figures 1 and 2 d d are the metallic bands or strips for
strengthening the setting. e is the binding screw, is the insulating material with
which the lead setting and the upper parts of the carbons are covered. The dotted
line indicates a suitable depth to which the upper ends of the carbons are
paraffined. Figure 7 is a plan view and Figure 8 a side view of a corrugated metal
strip d.
Figure 9 is a side view and Figure 10 a plan of an annular carbon plate the
carbons being cast into a lead setting by means of the mould Figures 3 and 4.
For very deep or long carbon rods I provide a setting at the bottom of the plate
as well as at the top or head and this setting may be of the same kind as the one
described for the top, which I need not therefore further illustrate; or the bottom
setting may be only insulating material alone.
This part of my invention is illustrated by Figures 11 and 12, the former being a
vertical section of an annular " plate of this construction placed in the annular
space between the pot A and the inner porous pot B. The setting y at the top of the
plate" as is described with reference to the previous figures while the setting hat
the bottom is of suitable insulating material such for instance as the one named. But
in order to give additional support to the insulating material and hold the carbon
rods well together at this place I tie them together first with lead. wire or asbestos
yarn or other suitable binding material; this wire or yarn is wound in and out
around the carbons first in one direction and then back in the opposite direction. Or
I may for the bottom setting of such carbon "plates" use a wood frame which may
be soaked in paraffin, or may use any other suitable support for the carbons at this
place.
Figure 13 is a plan view and figure 14 a side view of a carbon electrode made of
rods arranged ring fashion with a central rod cast with sufficient interstices for tho
exciting liquid at one end in lead in the manner described and at the other in
insulating material , or if the electrode is of short length the part h may be
omitted.
Figure 15 is a front elevation and figure 16 a vertical cross section of a flat
compound plate having the lead setting at the top, and the insulating material setting
at the bottom.

page_text: The bottom setting of insulating material may in all cases be done by means of a
mould.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed. 1 declare that what
I claim is
:-
First The mode of manufacture of compound carbon electrodes consisting in
placing the ends of carbon rods in moulds of the character described, pouring lead
around' them, inserting brass or other suitable lead coated metal strips in the molten
or plastic lead before or after pouring it in and subsequently coating the lead setting
with insulating materal and treating the rods with paraffin wax or the like substantially
as and for the purposes set forth.
Second-The constructions of compound carbon electrodes as described with
reference to the accompanying drawings.
Third-The employment in the lead setting of compound carbon plates of
strips of brass or other suitable material for stiffening the setting substantially as
set forth.
Fourth-Compound carbon plates consisting of carbon rods cast (at one or both
ends) into a frame of lead or other suitable metal or alloy with metallic strengthening
strips substantially as set forth.
Fifth Compound carbon plates consisting of carbon rods at one end cast into a
frame of lead or other suitable metal or alloy with metallic strengthening strips and
at the other end tied together with lead wire or other suitable material and set in a
frame of a suitable plastic insulating material substantially as set forth.
Dated this 2nd day of December 1007.
HENRY LIEPMANN.
By Jensen & Son,
77, Chancery Lane, London, W.C.,
Patent Agents.