IMPROVEMENTS IN GALVANIC BATTERIES
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and
W. Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents for an Invention of IMPROVEMENTS IN GALVANIC
BATTERIES communicated to him from abroad by Georges Gaëtan Louis Velloni,
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 29th May 1883.
ALEXANDER MELVILLE CLARK of the firm of A M and W Clark of 53 Chancery
Lane in the County of Middlesex Fellow of the Institute of Patent Agents
"IMPROVEMENTS IN GALVANIC BATTERIES [communicated to him from abroad
by Georges Gaëtan Louis Velloni, of Paris, France]
"
This Invention relates to an improved constant battery. The construction of
the battery is represented by way of example in the accompanying drawing and
will be described with reference thereto.
Figure 1 is a perspective view of a couple, and Figures 2 and 3 edge and top
views of the complete cell. Figure 4 represents the general arrangement for the
automatic supply of the sulphuric acid to the battery.
The cell consists of two carbon plates 6 preferably of large dimensions attached
to a supporting plate or cover of ebonite or other insulating material a, and of an
amalgamated zinc c placed between them. This zinc is immersed in a porous
vase or receptacle of perforated caoutchouc d which is represented as being of oval
form, and is attached to the ebonite plate a by clips or other means so as to be
readily dismounted. This vase or receptacle is filled with an exciting salt and the
couple is immersed in a rectangular cell. This mode of construction enables the
couple to be removed from the liquid during repose, and it is preferable when a
number of elements are used to provide a winch for raising them all at once.
To charge the battery I saturate water in the cold with trichromate of potash or
soda, and add for each litre of this liquid 60 cubic centimetres of ordinary
sulphuric acid. The trichromate of potash is prepared in the following way I
saturate at 80°, 10 litres of water with bichromate of potash, and add to this
solution 700 cubic centimetres of nitric acid at 40° and pour into crystallizers.
D

page_text: Whilst cooling, small orange red crystals deposit. The porous or perforated vase
is filled with crystals of trichromate of potash so that the zinc shall be surrounded
therewith on all sides. These crystals dissolve during the working of the battery
and maintain the liquid at the same degree of saturation.
The mode of preparation is similar in the case of soda. When the battery is
required to furnish a current for more than four hours, I combine with each
element a receptacle pouring drop by drop 15 to 20 c. c. of sulphuric acid per hour.
Under these conditions a powerful couple of great constancy is obtained This
constancy is due to the arrangement of the zinc in the salt which fills the porous
or perforated vase. The heat produced by the attack of the zinc facilitates the
solution of the crystals of trichromate which maintain the solution at the same
degree of saturation. The crystals absorb nascent hydrogen in becoming reduced,
thus obviating all polarization.
If it be desired to produce a very much more powerful battery, the battery may
be set up in the following way.
I added to 2 kilos of moist yellow chromate of soda, 1800 grammes of ordinary
sulphuric acid whereupon the chromate becomes oxidised and changes to a red
color. When the mass has become hard it is dissolved in 1 litre of hot water and
I add during cooling 100 cubic centimetres of nitric acid per litre of liquid; one
third of this solution which does not crystallize, mixed with water, employed for
charging the battery. The porous or perforated vase is filled with crystals of
trichromate of potash prepared according to the directions previously given. This
couple furnishes without the addition of sulphuric acid a current of a certain intensity
which is increased by adding 60 cubic centimetres or more of sulphuric acid.
Figure 4 shows the general arrangement for automatically supplying sulphuric
acid to maintain the current constant for a considerable time. The example shows
a battery of several elements in series, but it may be applied to any other
arrangement or to a single element. In this Figure a are the cells out of which
the elements b are shown raised. e is a bottle filled with filtered sulphuric acid,
and c is a glass distributing tube supplied therefrom and furnished with as many
drop nozzles d as there are cells to be supplied. In the mouth of the bottle e a
tube is inserted and is connected by an indiarubber tube with a bent tube h
whose free end i dips in a cup j filled with mercury. This tube h is carried by the
pivoted armature k of an electro magnet l. In the circuit of the battery is placed
an ampère meter m whose index needle is so arranged as when the intensity of the
current diminishes to a given degree, to close the circuit of a battery n through
the electro magnet 7 which thereupon attracts its armature k and unseals the tube h
so as to permit air to enter the receptacle e to enable sulphuric acid to flow out
through the nozzles d to replace that which has become decomposed by the active
electrodes. The battery thereby regains its initial vigor and the needle of the
ampère meter rises and breaks the circuit of battery n whereupon tube h falling,
is again sealed by the mercury and the flow of sulphuric acid is arrested until the
intensity of the current again diminishes to the predetermined limit when the
same action is repeated and so on. This arrangement enables the battery to
gradually absorb as much sulphuric acid as may be required so that the intensity
of the current shall never diminish more than a quarter of an ampère.
The parts of this general arrangement may be varied in form arrangement and
operation. For instance instead of sealing the air tube by mercury,
may use a
stopper or a valve or a nipper compressing the indiarubber tube or any other
device actuated by the motion of the armature k, and the electro magnet 7 may be
excited by the current of the battery itself or a derivation thereof instead of by a
special battery.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
29th November 1883.
ALEXANDER MELVILLE CLARK, of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents.
"IMPROVEMENTS IN GALVANIC BATTERIES A communication to me from abroad
by Georges Gaëtan Louis Velloni of Paris, France.
"
This Invention relates to an improved constant battery. The construction of
the battery is represented by way of example in the accompanying drawing and
will be described with reference thereto.
Figure 1 is a perspective view of a couple, and Figures 2 and 3 edge and top
views of the complete cell. Figure 4 represents the general arrangement for the
automatic supply of the sulphuric acid to the battery.
The cell consists of two carbon plates b preferably of large dimensions attached
to a supporting plate or cover of ebonite or other insulating material a, and of an
amalgamated zinc plate e placed between them. This zinc plate is immersed in a
porous vase or receptacle of perforated caoutchouc d which is represented as being
of oval form and is attached to the ebonite plate a by clips or other means so as
to be readily dismounted. This vase or receptacle is filled with an exciting salt
and the couple is immersed in a rectangular cell. This mode of construction
enables the couple to be removed from the liquid during repose and it is preferable
when a number of elements are used to provide a winch for raising them all at
once.
To charge the battery I saturate water. in the cold with trichromate of potash
or soda, and add for each litre of this liquid 60 cubic centimetres of ordinary
sulphuric acid. The trichromate of potash is prepared in the following way :-I
saturate at 80°, 10 litres of water with bichromate of potash and add to this
solution 700 cubic centimetres of nitric acid at 40° and pour into crystallizers.
Whilst cooling, small orange red crystals deposit. The porous or perforated vase
is filled with crystals of trichromate of potash so that the zinc shall be surrounded
therewith on all sides. These crystals dissolve during the working of the battery
and maintain the liquid at the same degree of saturation. The mode of preparation
is similar in the case of Soda. When the battery is required to furnish a current
for more than four hours, I combine with each element a receptacle pouring drop
by drop 15 to 20 c. c of sulphuric acid per hour. Under these conditions a powerful
couple of great constancy is obtained.
To give an example, the element may consist of two carbon plates of 10 milli-
metres in thickness, 80 millimetres in breadth and 250 millimetres in height and one
zinc of 7 millimetres in thickness 50 millimetres in breadth and 240 millimetres in
height immersed in a porous or perforated vase filled with 300 grammes of crystals of
trichromate of potash. The couple set up with the liquid above indicated and
provided with a small sulphuric acid container has given the following constants.
60
E = 2000
TO
I = 710
15
1000
The same element short circuited through the ampère meter of Mess" Deprez &
Carpentier having a resistance of 110 th of an ohm, maintained the needle at an
intensity of 7,8 ampères for 18 consecutive hours. At the end of this time the
crystals of trichromate of potash were completely exhausted and the reaction
produced by the electric current had converted the solution of this chromate in
presence of the sulphuric acid, into green sulphate of chromium and as these salts
are uncrystallizable there will be no deposit adhering to the carbons or any other
part of the element

page_text: is again sealed by the mercury and the flow of sulphuric acid is arrested until the
intensity of the current again diminishes to the predetermined limit when the
same action is repeated and so on. This arrangement enables the battery to
gradually absorb as much sulphuric acid as may be required so that the intensity
of the current shall never diminish inore than a quarter of an ampère.
The parts of this general arrangement may be varied in form arrangement and
operation. For instance instead of sealing the air tube by mercury, I may use a
stopper or a valve or a nipper compressing the indiarubber tube or any other
device actuated by the motion of the armature k, and the electro magnet / may be
excited by the current of the battery itself or a derivation thereof instead of by a
special battery.
This automatic arrangement for supplying the sulphuric acid, also serves to
regulate the intensity of the current to suit the requirements of the circuit in
which the battery is placed. This is effected in the following manner. The ampère
meter m placed in the circuit of the battery, is so arranged that the movable
contact o may be placed opposite any given degree of the ampère meter, and when
any desired intensity is to be obtained, the liquid is acidulated until the pointer
moves opposite the degree corresponding to the intensity desired, and the movable
contacto is then placed at this point.
The battery can never in working, fall below the desired intensity without
closing the circuit which actuates the electro magnet for regulating the supply of
sulphuric acid to each of the elements; the battery is thus maintained at a
constant intensity. The sulphuric acid added to each of the elements regenerates
the solution of bi-chromate of chloride of potassium decomposed by the chemical
action.
The ampère meter may in certain cases be replaced by clockwork arranged to
close the circuit which actuates the electro-magnet by means of an index hand
making contact with a stud. In this case the flow of the sulphuric acid can
only be regulated approximately, and the ampère meter is therefore to be
preferred.
Having described the nature of the said Invention and the manner of
performing the same I declare that what I claim as the Invention to be protected
by the herein before in part recited Letters Patent is:
1 In a galvanic battery of constant intensity, the employment of trichromate
of potash or superoxygenated bichromate of potash or of soda, whereby much
more electricity is generated than in batteries charged with less oxygenated
chromates.
or
2nd The arrangement of the zinc, immersed in a perforated porous vase
receptacle and containing the exciting salt which in dissolving under the calorific
action of the current, maintains the solution at the same degree of saturation and
thus obviates polarization
3rd The mode of charging the battery by means of an automatic magnetic
arrangement consisting in the combination with the battery of an ampère meter
whose pointer by contact with a stud placed at any given degree of the dial
closes the circuit through an electro-magnet which by attracting an oscillating
armature turns on the supply of acid the whole substantially as described for the
purpose specified.
. In witness whereof, I the said Alexander Melville Clark, have hereunto set my
hand and seal this Twenty eighth day of November A. D. 1883.