Improvements in Electrodes for Electrolytic Purposes.
Year: 1896

page_text: Date of Application, 23rd May, 1896
Complete Specification Left. 23rd Feb.. 1897-Accepted, 15th May, 1897
Improvements in Electrodes for Electrolytic Purposes.
I, ERNEST AUGUSTE GEORGES STREET, of 95 Boulevard Beaumarchais, Paris, in
the Republic of France, Engineer, do hereby declare the nature of this invention to
be as follows:-
In the electrolysis of substances which produce a solid deposit upon the negative
electrode and particularly in the electrolysis of salts of the various metals, metal
plates or rods are generally employed for the cathode.
Frequently the deposit, especially if it entirely surrounds the plate, rod or bar
forming the cathode, adheres so firmly thereto, that it can only be detached therefrom
with the greatest difficulty, according to the nature of the substance electrolyzed, a
certain quantity appearing, as it were, incrusted thereon.
The inconvenience resulting from the above circumstance is remedied according to
the present invention by providing a cathode, which after the precipitate has been
deposited upon it, is capable of having its cross section and therefore its outer surface
reduced. The deposit forms a kind of hollow cast of which the cathode forms a
contractible core; so that when the bulk of the cathode is diminished, the film or
layer of deposit can be removed therefrom with the greatest facility.
The cathode is formed of a thin sheet, preferably of metal, wound upon itself one
or more times by hand or otherwise.
After the precipitate has been deposited, it is only necessary to apply a suitable
force at the free extremity of the sheet forming the cathode to coil it more tightly and
so to diminish its cross section and consequently its outer surface. The deposit is thus
automatically detached and when it is removed, the cathode by reason of its elasticity
will resume its normal dimensions.
In cases where sufficient force cannot be exerted by ordinary means upon the free
extremity of the cathode to detach the deposit, one or more appropriate projections
may be provided upon the interior surface of the tube which forms the cathode for the
purpose of being acted upon by a suitable tool which thus effects the required winding
or contraction.
In order that the resistance of the cathode may be increased at the part where the
current is received, a blade, solid rod or bar conforming to the shape of the cathode
may be introduced therein at the extremity which projects from the electrolyte.
Electrodes may be manufactured in accordance with this invention of various shapes
and sizes.

page_text: Improvements in Electrodes for Electrolytic Purposes.
I, ERNEST AUGUSTE GEORGES STREET, of 95 Boulevard Beaumarchais Paris, in
the Republic of France, Engineer, 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:-
In the electrolysis of substances which produce a solid deposit upon the negative
'electrode and particularly in the electrolysis of salts of the various metals, metal plates
or rods are generally employed for the cathode.
Frequently the deposit, especially if. it entirely surrounds. the plate, rod or bar
forming the cathode, adheres so firmly thereto, that it can only be detached therefrom
with the greatest difficulty according to the nature of the substance electrolyzed a
certain quantity appearing, as it were, incrusted thereon.
The inconvenience resulting from the above circumstance is remedied according to
the present invention by providing a cathode, which after the precipitate has been
deposited upon it, is capable of having its cross section and therefore its: outer surface
, reduced. The deposit forms a kind of. hollow cast of which the cathode forms the
contractible core; so that when the bulk of the cathode is diminished, the. film or
layer of deposit can be removed therefrom with the greatest facility..
The invention is shown in the accompanying drawing in which
Figures 1, 2 and 3: represent in horizontal. section by way of example three. forms
of cathode constructed according to the present invention..
As will be seen this cathode is formed of a thin sheet, preferably of metal, wound
upon itself one or more times. This winding or coiling may be effected: by hand or
mechanically, by using any appropriate mandril.
After the precipitate has been deposited, it is. only necessary to apply a suitable
force at the free extremity of the sheet forming the cathode to coil it more tightly and
so to diminish its cross. section and consequently, its outer surface, the sheet of metal,
thus receiving the tendency of becoming wound up upon itself to a still greater
degree. The deposit is thus automatically detachedi and, when it is removed, the
cathode by reason of. its elasticity will resume its normal dimensions..
In cases where. sufficient force cannot be exerted: by ordinary means upon the
free extremity of the cathode to detach; the: deposit,. one or more appropriate
projections may be provided upon the interior surface of the tube which: forms the
cathode for the purpose of being acted upon. by a suitable tool. so as to effect the
required winding or contraction..
In order that the resistance of. the cathode may be increased at the part where the
current is received, a blade, solid: rod or bar. conforming, to the shape of the cathode
may be introduced therein at the extremity which projects from the electrolyte...
Electrodes may be manufactured in accordance with this invention of various shapes
and sizes.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I' declare that what
.1 claim is :-
A cathode for use in the electrolizing of substances producing a solid deposit on
the negative electrode, the characteristic feature of this cathode being that after the
deposit having been effected thereon, it can be reduced in size, the object being to
enable the deposit to form a film or layer which can be very easily detached; the said
cathode being for this purpose formed by a thin sheet, preferably of metal, wound
one or several times upon itself; the reduction of the cathode in size being subsequently

page_text: obtained, after the deposit has been formed thereon, by winding the sheet, constituting
the cathode upon itself.
Dated this 23rd day of February 1897.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.