Improvements in Electric Accumulators.
Year: 1898

page_text: Date of Application, 19th July, 1898-Accepted, 4th Mar., 1899
Improvements in Electric Accumulators.
I, EWALD LEIMER, of 110, Kôpnickerstrasse, Berlin, in the Empire of Germany,
Engineer, do hereby declare the nature of my invention and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement :---
It is well known that the electrode of an accumulator will be better suited for
effecting a rapid discharge the greater the proportion of the contact surface of the
lead frame is to that of the active mass resting on the same and the thinner the cross
section of the latter, taken at right angles to the contact surface. For this reason
the Planté accumulator offers the greatest possibility of a rapid discharge with an
exceptionally large amount of current, the contact surfaces of these accumulators
being very large and the oxidising layer (active mass) resting thereon being very thin.
Unfortunately the capacity of these accumulators is very low; the so called "mass
electrode attains a capacity nearly 30% higher, but this obviates the possibility of a
These circumstances
rapid discharge i.e. the discharge with a very strong current.
"
are explained by the fact that the contact surface of the frame is very small and the
active mass very large. It is often desirable to render a mass plate electrode suitable
for a rapid discharge, without, however impairing the high capacity and without
deteriorating the durability of the active mass. According to the present invention
this result is attained in a very simple manner, without altering the plate itself,
whilst at the same time the electrodes are rendered more durable. If the mass
electrode is covered at both sides with a perforated plate of metal which is capable of
resisting the action of acids and will not oxidise being a lead alloy or compound of
lead and antimony containing about 4-10% of antimony, said plate being very thin,
and the electrodes thus formed are arranged in a cell in such manner that the positive
and negative plate systems are insulated by means of specially formed ebony combs,
forming together a compressed whole, the accumulator thus formed may be charged
just as quickly as a Planté accumulator, without increasing the weight of the same to
any noticeable extent, the full capacity of the mass electrodes will be attained and at
the same time the active mass rendered more durable, in that the perforated plates
prevent the same from falling out, and drive the gas bubbles, invariably formed
by a large amount of current, from the active mass to the exterior surface of the
plates. Thus the destroying influence of the gas bubbles on the soft active mass is
avoided.
And in order to render the present specification more easily intelligible reference
is had to the accompanying drawing in which similar letters of reference denote
similar parts throughout the several views:
Fig. 1 is a side elevation and
Fig. 2 a horizontal section of an accumulator constructed according to the present
invention.
In the bottom of the cell a are arranged prismatic bearing beams b b¹ which carry
the whole plate system. In the first place an ebonite plate to dis arranged,
behind which is mounted a negative electrode e, behind this again is a hard lead
comb 8-14 and behind this again a perforated ebony plate f, there behind an ebony

page_text: comb (15-21 then a positive electrode g, then a comb of hard lead 22-26 then an
ebonite plate f¹, a comb of hard lead d20-36, then a negative electrode e¹ and so on in
the same order.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
Accumulator construction for obtaining a rapid discharge with a large amount of
current and enhanced durability of the mass electrodes, characterised by covering the
whole effective surface of the active mass, with perforated thin plates of non-
oxydisable metal, capable of resisting the action of acids, any number of such
positive and negative plates being insulated by means of suitably formed inter-
mediate layers and compressed together within one cell in the manner and for the
purpose substantially as described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.