An Improvement in Electrodes for Secondary Voltaic Batteries.
Year: 1896

page_text: Date of Application, 16th Sept., 1896-4ccepted, 7th Nov.. 1896
AMI LETE SPECIFICATION.
[Communicated from abroad by RALPH JOHN WALTER GRINDLE, of Hotel
de Paris, Dieppe, in the Republic of France, Gentleman.]
An Improvement in Electrodes for Secondary Voltaic Batteries.
I, HAROLD IMRAY of No. 28 Southampton Buildings, Chancery Lane in the
County of London, Chartered Patent Agent, 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 Specification No. 8728 of 1895 there is described a construction of
electrode for secondary voltaic batteries consisting of a plate of lead alloyed with
a little antimony, having through it a number of holes which are filled with plugs,
each consisting of a strip of lead which is transversely ridged and furrowed and is
rolled into the form of an approximately cylindrical roll which is forced into a
hole of the plate. The form of lead strip which is found most serviceable for
this purpose is of the kind shewn in Fig. 5 of the drawings accompanying the
said specification, that is to say a strip flat on the one side and ridged and furrowed
only on the other. There is however a disadvantage attending this form resulting
from the fact that, when the electrodes are in use, the thin films of lead at the
bottoms of the furrows soon become oxidised, so that there is an interruption of
conduction from ridge to ridge, and therefore defective conduction throughout the
plug. The object of this invention is to obviate this defect, which I do by
forming the strip with a central longitudinal ridge connecting all the transverse
ridges.
Fig. 1 of the accompanying drawings is a plan, Fig. 2 is a transverse section,
and Fig. 3 is a perspective shewing part of a strip according to my present
invention, Fig. 4 shewing it partly rolled up. It will be seen that along the
middle of the strip there is a longitudinal ridge A dividing each transverse furrow
in halves.
When the plug formed by rolling up such a strip is fixed in a hole of the
electrode plate, the electrolyte liquid has free access from each side to the
middle of the plug, and although the thin lead at the bottom of each half furrow
soon becomes oxidised, ceasing to conduct from transverse ridge to ridge, the
thicker metal constituting the central longitudinal ridge, becoming oxidised only
superficially, maintains good conduction throughout the whole roll.
Although in the drawing, I have shewn the cross ridges of triangular section, they
might obviously be of other forms, and the longitudinal ridge might be of the same
form as the transverse ridges or of a different form.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
For filling the holes of an electrode plate for a secondary voltaic battery, plugs
each consisting of a rolled up strip of lead, having on its one side transverse ridges
and furrows, all the ridges being connected by a central longitudinal ridge,
substantially as and for the purpose set forth.
Dated this 16th day of September 1896.
ABEL & IMRAY,
Agents for the Applicant.