Improvements in or relating to Secondary Batteries.
Year: 1889

page_text: Date of Application, 23rd Sept., 1889
Complete Specification Left, 23rd June 1890-Accepted, 2nd Aug., 1890,
PROVISIONAL SPECIFICATION.
Improvements in or relating to Secondary Batteries.
I, PAUL JOSEPH RODOLPHE DUJARDIN, of 28 rue Pavin, Paris, in the Republic of
France, manufacturer, do hereby declare the nature of this invention to be as
follows:-.
The object of this invention is
1st, to facilitate the construction and transport of accumulators, by separating the
plates or poles by a porous substance such as grains of infusorial earth, obtained by
burning natural infusorial earth as for pottery. The size of each of the grains of
porous matter is of about millimetres in diameter.
2nd, to regulate the discharge of these accumulator batteries by employing an
automatic regulator composed substantially of an electro magnet of great resistance
and so mounted in the circuit that by means of its armature a current is passed
through one or other of two electro magnets controlling the resistances according as
One of these electro magnets
the potential of the current increases or decreases.
through its armature and suitable gearing operates so as to insert resistances into
the circuit and the other of these electro magnets by similar meaus operates so as to
withdraw the resistances from the circuit. The resistances being finely graduated an
absolute regularity to the discharge current may thus be given.
Dated this 93rd day of September 1899.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Secondary Batteries.
I PAUL JOSEPH RODOLPHE DUJARDIN of 28 rue l'avin, Paris, in the Republic of
France, manufacturer, do hereby declare the nature of this invention and in what
manuer the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
The electrical storage plates or secondary batteries should be kept apart, and in
cases where it is desired that the cells should be capable of displacement such plates
or poles should also be secured as firmly as possible within the cases containing
them.
To attain this result I fill the spaces between the plates with a substance proof
against the action of sulphuric acid and offering no appreciable electrical resistance,
while it is also endowed with considerable porosity when submitted to the action of
liquids.
This material known under the name of artificial white stone and being really a
species of porous infusorial earth or silex is obtained by compressing under considerable
This
pressure a paste obtained by impregnating very fine white sand with water.
silicious paste is then burnt in a kiln like ordinary pottery, and then reduced to a
coarse powder, the grains of which are about one eighth of an inch in diameter. By
filling the cells of the secondary battery with this granulated material uniform
distances are ensured between the plates, and the whole of the cells form a
compact mass capable of resisting the most violent shocks without injury to the
pole plates.
'
It is a fact well known to electricians that secondary or storage batteries are
capable of varying to a very great degree in voltage according to the required supply
of current and also according as they are more or less fully charged.
These variations, the limits of which may be set down as from 2.1 volts to 1.8 volts

page_text: are attended by very serious drawbacks in batteries. For example in a battery
of 50 cells newly charged the voltage attains from 104 to 105 volts when only one
lamp is in use, while it goes to 100 volts when ten incandescent lamps are used, and
to 95 volts when thirty lamps are used at a time. After a few hours operation the
voltage is further reduced to 90 volts which is the minimum.
To remedy this inconvenience an automatic rheostat, such as illustrated in
Figures 1, 2 and 3 of the accompanying drawings has been devised, whereby these
differences of voltage are adjusted with great precision.
Two electro magnets E E' alternately attract the plates A, B, provided with pawls
which are adapted to engage with ratchet wheels C, D. These ratchet wheels are
mounted upon shafts provided with pinions F F which impart motion to a toothed
wheel to which, is secured a lever or arm G, H carrying the brush at its end.
One of the ratchet wheels tends to turn the lever G, H from right to left and the
other ratchet wheel tends to turn the brush in the opposite direction.
In order to obtain this reciprocating motion automatically the electro magnets E E'
are connected as shown in Figures 1, 2 and 3 on one side to the abutting screws V VI
of a relay of great resistance and considerable sensitiveness placed in series within
the circuit of the lamps.
A suitable spring is controlled in such manner that for the average voltage the
contact S is retained in equilibrium between the two stops or screws V V¹. If the
electro motive force increases the pallet is slightly attracted and makes contact with
the screw Vand inversely it will come into contact with the screw V when the
current descends below the average voltage.
A current flowing from the accumulators is thus caused to pass into either of
the electro magnets E Eaccording as the electro motive force of the battery rises
above or falls below the average voltage by a fraction of a volt. This current
completes its circuit through the contact of an angle piece or bolt T T¹.
When the current attracts the soft iron plate B the rod carrying the pawl moves
this bolt and breaks the circuit through the electro magnet. Whereupon the said
plate B moves back under the action of the spring and along with it brings the
bolt into contact again so that the electro magnetic attraction can once more take
place.
It will be seen that the contact is only broken when the useful effect has been
obtained a condition which the system known as the vibrating bell system (trembleurs
de sonnerie) possesses.
The arm or lever G H is adapted to go into frictional contact with a series of
plates or resistance collectors (figure 3) and it is directly connected with one of the
pawls of the storage battery through the body of which it cominunicates with the
two bolts TT.
Having now particularly described and ascertained the nature of the said inven-
tion and in what mauner the same is to be performed, I declare that what I
claim is
1. The employment of porous infusorial earth or silex in a granular condition for
the purpose of maintaining the plates within the secondary or storage batteries at
the desired distances apart substantially as described.
2. The arrangement of an automatic rheostat substantially as herein described
whereby differences of potential in discharging electro storage batteries or accumu-
lators are adjusted mainly consisting of a relay of great resistance in the circuit so
as to operate alternately two electro magnets adapted to increase or diminish the
resistance in the discharging circuit.
Dated this 23rd day of June 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicant.