Improvements in or relating to Electric Accumulators.
Year: 1890

page_text: Date of Application, 7th June, 1890
Complete Specification Left, 16th July, 1890-Accepted,- 20th Sept., 1890
PROVISIONAL SPECIFICATION:
Improvements in or relating to Electric Accumulators.
A communication from abroad by ISAAC PERAL, of San Fernando, Cadiz, in the
Kingdom of Spain.
1, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool and 6, Bank Street, Manchester, both in
the County of Lancaster and 323 High Holborn in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention to be as follows :--
This invention relates to improvements in accumulators applicable for all industrial
purposes.
The essential characteristics of a good accumulator are:-
That it be of the greatest possible capacity with relation to its weight and size;
that the plates and poles (terminals) be of the greatest durability possible; and that
the active layer of packing or paste filled into the plates does not readily fall off.
To ensure these advantages and also that of easy manipulation-above all in
electric charging and discharging-is the object of the improvements about to be
described.
Accumulators, have hitherto usually been composed of lead plates, or plates of an
alloy of lead and antimony to which some makers add mercury, between or into
which the active layer of packing or paste is filled in, the latter being composed
of oxide of lead, kneaded in water acidulated with sulphuric acid. These oxides
are usually minium for the positive, and litharge for the negative plates.
Leaving the filling or paste out of the question for the moment, as it does not form
a part of the present invention, the plates, which form an essential part of this
invention, will now be described.
In order to give the required compactness to the union of paste and metal composing
said plates, the latter usually consisted of a pretty thick lead grating, which, however,
does not obviate the falling off of some bits of the active matter, for want of proper
cohesion, nor the rapid destruction of the grating (above all in the positive plates),
nor the warping of said positive plates for want of sufficient stiffness transversely.
And to all the above drawbacks must be added the excessive ratio which the total
weight of the plates bears to the total weight of packing or paste.
To do away with all these obstacles, the plates are made of an improved form.
Each plate is composed of an outer rectangular frame of the metal and has a series of
stout transverse ribs with a long notch or groove along each side. These grooves
(after the plate has been removed from the mould in which it has been cast) are
opened out by any suitable device, so as to form recesses in which the paste may be
securely held. Smaller ribs connect the cross ribs at right angles, and, if desired,
these are in turn connected by parallel ones. The form of the ribs completely
obviates the falling off of the packing or paste; and these same ribs, in union with
the cross ribs afford, to the plates, considerable stiffness or rigidity, against bending.
The thinner cross ribs facilitate electrical conduction across the paste, and afford
stronger cohesion between the paste or packing and the grating. The sides and ribs
being very thick ensure very long duration to the plates, and as the ratio of weight of
the packing or paste with the total weight of the plates becomes considerably increased,
by this means a great augmentation of accumulating capacity is obtained.
The positive plates are somewhat thicker than the negative, so that their accumu-'
lating capacity between them may be in better proportion, and both positive and
negative are cast with teeth at each side in order that, on arranging the positive
and negative groups, the positive are united together and the negative united together.

page_text: by combs having corresponding recesses as the teeth, so that a complete stiffness or
rigidity may be secured in each group. The plates of every group are connected
together by means of cross bars having binding screws or ribbons which serve as
poles or terminals to the plates, all of which is done by one casting which is soldered
autogenially to the said screws of the plates in a special mould, using an alloy of
lead and antimony, in very variable proportions according as the grating be of this
same alloy or of only lead, the studs or screws aforesaid being amalgamated with
mercury to hinder oxidation, which is antagonistic to autogenial soldering. This
process of soldering the bars and poles has the advantage of avoiding the use of
any extraneous metal in the soldering, and the form of the poles will facilitate
the improvements of which a description is given as follows:-
When the accumulators are to be used on board ship or in closed up compartments
or otherwise, it is of great importance that the cells be closed, and in many cases it is
better that they should be hermetically closed, and even sealed. In this case apertures
are made in the lids with threaded or sealed plugs or stoppers, so that through same
the density of the baths can be observed and measured, and two other borings are
provided through which the poles project. Lead pipes pass through the lid of the
case, the object of which is the following:-
-
On charging at high rate (régime) and above all at the termination of the charge,
large quantities of hydrogen and oxygen gases, mixed with ozone, are produced,
which give rise to annoyance, deterioration and not infrequently danger. Now these
pipes are a complete protection against the action of these gases. If in a battery of
accumulators the pipes of the cells are connected with the other ones next them by
means of flexible india-rubber or other suitable tubes, a current of air may be caused
to pass through the interior of the cells by means of a ventilator, or the like, which
current, entering at one end of the row of cells, carries away all the gases produced
in the interior of the cells and expels them at the other end, whence they are carried
into the open air. This can be done by arranging the cells in one single row, if the
battery be short, or by bifurcation, in several, should the battery be composed of a
large number of cells. Twenty to thirty elements per row may be found to be
practically a good number for the pressure of air given generally by the ventilators.
In the event of there being several rows, a single ventilator, with several mouth pieces
or nozzles will supply the air for as many rows as its outlet area shall permit, taking
into account the area of the india-rubber tubes, whose total area should be nearly
equal to that of the exit orifice of the ventilator.
Lastly, the other improvement in accumulators; to render their management
thoroughly practical, is the following:-
It has been observed that in the management of batteries of accumulators, it is
very difficult, if not impossible, to keep them all in an equal state of charge, unless
one adopt the tiresome expedient of giving frequent additional or partial charges
to the less saturated elements. Mr. Peral has become convinced of the importance
of devising a means or method of eliminating, automatically those cells that first
become fully saturated or charged in the process of charging, without having to
stop the charging at all, because, if the charging has to be suspended when some
of the cells are fully charged, it leaves the less charged cells short of charge, or,
if the charging be continued, it overcharges the already saturated cells and either
of these alternatives is prejudicial to the existence of the accumulator.
The means employed to obtain the automatic elimination are as follows, and may
be located in any part, but preferably on the lid of the accumulator :—
An electro-magnet, of small size but with great electric resistance compared to that
of the interior or the inside of the accumulator, has the terminals of its coil in contact
with the two poles of the latter, and its circuit can be interrupted by means of a peg or
cut out of any kind that may permit the current to be always cut of, or closed a few
moments before commencing the charge. Besides the current of the electro-magnet
"there is on the lid another circuit comprising the armature of the electro-magnet, (the
said armature being under the influence of an antagonistic spring) and a resistance

page_text: coil the importance of which depends on the rate (régime) of charge required by the
accumulator in accordance with the weight of its plates. The mode of working this
arrangement or method is as follows:-
Both the antagonistic spring and the resistance of the electro-magnet are regulated
in such manner that the force of attraction of the electro-magnet for its armature is
less than the mechanical force opposed by the antagonistic spring, whilst the difference
of potential at the poles is that which corresponds to the state of saturation, but when
the saturation is effected-which happens when the entire charge is employed in pro-
ducing gases which the plates do not take up-it is a well known fact that, owing to
the presence of said gases, the difference of potential between the electrodes rises
2.5 volts. or thereabouts, and by reason of this rise, the current circulating in the coil
of the electro-magnet, which, during the entire charging, is only a small fraction of
an ampère, increases in intensity, by which the strength of the electro-magnet
becomes also increased and attracts the armature, and, by the closing, then, of the
circuit, the whole current of the charge passes by the resistance coil. By this means
the production of gases ceases, and the accumulator does not become overcharged.
By this new method, the charging can be continued with impunity until the most
backward cells are saturated and all are equalised. When the action of the charging
current has ceased, the difference of potential, 2.5 volts., sustained by said current
rapidly decreases, as is well known; and, in consequence of this, the force of the
electro-magnet is again lessened the armature is pulled by the antagonistic spring,
the shunt circuit is again broken and all the accumulators become, once more,
automatically and simultaneously in open circuit, the shunt circuits of the electro-
magnets alone remaining closed until these are broken by operating the pegs. The
screw which regulates the tension of the antagonistic spring may be graduated or
gauged, so that, by this medium, the volts. and decimals may be measured during the
charge, because the decimals of volts., varying in the different degrees of charge, the
force of the electro-magnet varies also and thus special voltmetres to observe
the charging are not required.
Dated this fith day of June 1890
WM. P. THOMPSON & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Electric Accumulators.
A communication from abroad by ISAAC PERAL, of San Fernando, Cadiz, in the
Kingdom of Spain.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, and 323 High Holborn, in the County of Middlesex, Civil
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 :-
This invention relates to improvements in electric accumulators or secondary
batteries applicable for all industrial purposes.
The essential characteristics of a good accumulator are:-
That it be of the greatest possible capacity with relation to its weight and size;
that the plates and poles (terminals) be of the greatest durability possible; and
that the active layer of filling or paste packed into the plates does not readily
fall off.
To ensure these advantages and also that of easy manipulation-especially in
charging and discharging-is the object of the improvements about to be described.
Accumulators have hitherto usually been composed of lead plates, or plates of an
alloy of lead and antimony to which some makers add mercury, hetween or into which
the filling or paste of active material packed, the latter being composed of oxide of

page_text: lead, kneaded in water acidulated with sulphuric acid.
minium for the positive, and litharge for the negative plates.
These oxides are usually
Leaving the filling or paste out of the question for the moment, as it does not form
a part of the present invention, the plates, which form an essential part of this
invention, will now be described.
In order to give the required compactness to the union of paste and metal com-
posing said plates, the latter have been usually made of a pretty thick lead grating
or skeleton body, which, however, does not obviate the falling off of some bits of the
active material for want of proper cohesion, nor the rapid destruction of the body
(above all in the positive plates), nor the warping of said positive plates for want of
sufficient stiffness transversely. And to all the above drawbacks must be added the
excessive ratio which the total weight of the plates bears to the total weight of filling
or paste, this excessive ratio tending to reduce the accumulator capacity.
To do away with all these obstacles, the plates are made of an improved form as
illustrated in the accompanying drawings; in these,.
Figures 1, 2 and 3 show a plate as it comes out of the mould, Figure 1 being a side
elevation, Figure 2 a vertical section, and Figure 3 a horizontal section.
Figures 4, 5 and 6 are respectively side elevation, vertical section and plan of a plate
after it has been opened out by pressure as described below.
Figure 7 is a transverse section of an accumulator containing a number of
elements.
Figure 8 is a side view of the same, the outer wall of the cell or casing being
removed, and
Figure 9 is a plan of the cell.
Each plate is composed of an outer rectangular frame A of the metal and has a
series of stout transverse ribs aa with an elongated notch or groove along each side.
These grooves (after the plate has been removed from the mould in which it has been
cast) are opened out (as shown in Figures 4 and 5) by any suitable device, such as
a double stamp, so as to securely hold the paste within the recesses between said
ribs. Smaller cross ribs bb connect the ribs a a at right angles, and the spaces
between may again be subdivided by ribs c c. The form of the ribs a completely
obviates the falling off of the filling or paste, and they, in conjunction with the cross
ribs b, afford considerable stiffness or rigidity to the plates against bending. The
thinner cross ribs c facilitate electrical conduction across the paste, and afford stronger
cohesion between the paste or filling and the plate. The sides A and ribs a and b,
being very thick, ensure a very long duration of the plates, and as the ratio of the
weight of the filling or paste to the total weight of the plates is by these improvements
considerably increased, by this means a great augmentation of accumulating capacity
is obtained.
The positive plates are somewhat thicker than the negative, so that their accumu-
lating capacity may be in better proportion, and both positive and negative plates are
cast with ears d at each side in order that, on arranging the positive and negative
groups, the positive and the negative may be united together respectively by bars nn
having recesses or slots corresponding to the ears &. A thorough stiffness or rigidity
is thus secured in each group.
The plates of each group are connected together by means of cross bars e and fixing
studs (see Figures 7, 8 and 9) which serve as poles or terminals to the plates. The
entire connection is effected by one casting which is soldered autogenially to the said
fixing studs of the plates in a special mould, using an alloy of lead and antimony, in
very variable proportions according as the plate is of this same alloy or of only lead,
the studs being also amalgamated with mercury to hinder oxidation, which is
antagonistic to autogenial soldering. Each cross bar e is provided with a projecting
stud F. These studs F form the poles or terminals of the entire cell. The above
method of soldering the bars and poles has the advantage of avoiding the use of any
extraneous metal in the soldering, and the form of the poles F will facilitate the
improvements of which a description is given as follows:-
When the accumulators are to be used on board ship or in closed up compartments

page_text: or otherwise, it is of great importance that the cells be closed, and in many cases it
is better that they should be hermetically closed, and even sealed, see Figures 7, 8
and 9. In this case, apertures are made in the lids with threaded or sealed plugs or
stoppers g', so that through them the density of the electrolytic fluid can be observed
and measured, and two other apertures are provided through which the poles F
project. Lead pipes also pass through the lid of the case, the object of which is
the following
--
On charging at a high rate (régime) and above all at the termination of the charge,
large quantities of hydrogen and oxygen gases, mixed with a small quantity of ozone,
are given off which give rise to annoyance, deterioration and not infrequently danger.
Now these pipes are a complete protection against the injurious action of these gases.
For, if in a battery of accumulators the pipes of each case are connected with those of
the cases on either side of them by means of flexible india-rubber or other suitable
tubes, a current of air may be caused to pass through the interior of all the cells of
the battery by means of a ventilator, or the like, which current, entering at one end
of the roll of cells, carries away all the gases produced in the interior thereof and
expels them at the other end, whence they are carried into the open air. This can be
done by arranging the cells in one single row, if the battery be a small one, or by
bifurcation, that is, by arrangement in several rows if the battery be composed of a
large number of cells. Twenty or thirty elements per row may be found in practice
to be a convenient number for the pressure of air given generally by the ventilators.
In the event of there being several rows, a single ventilator, with several mouth
pieces or nozzles, will supply the air for as many rows as the area of its outlet
shall permit having regard to the area of the india-rubber connecting tubes. The
total area of the latter should be nearly equal to that of the exit orifice of the
ventilator.
It has been observed that, in the management of batteries of accumulators, it is
very difficult, if not impossible, when charging, to keep them all charged to an equal
amount unless one adopt the tiresome expedient of giving frequent additional or
partial charges to the less saturated cells. Mr. Peral has become convinced of the
importance of devising a means or method of eliminating automatically those cells
that first become fully saturated or charged in the process of charging, without having
to stop the operation of charging at all. If the charging has to be suspended, when
some of the cells are fully charged, it leaves the less charged cells only partially
saturated, or, if the charging be continued until all the cells are saturated, the cells
which were first saturated become overcharged and either of these alternatives is
prejudicial to the existence of the accumulator.
The means employed to obtain the above automatic elimination are as follows, and
the said means may be located in any part, but preferably on the lid of the accumulator
as shown in Figures 7, 8 and 9:-
An electro-magnet h, of small size, but with a great electric resistance compared to
that of the interior of the accumulator, has the terminals of its coil in electric con-
nection with the two poles F of the accumulator and its circuit can be interrupted by
means of a circuit plug or switch ¹ of any suitable kind, by means of which the
current may at any time be broken or by which the circuit may be closed a few
moments before commencing the charge. Besides the circuit of the electro-magnet h
there is on the lid another circuit j k l m comprising the armature k of the electro-
magnet (the said armature being controlled by a retracting spring p) and a resistance
coil r, the importance of which depends on the rate (régime) of charge required by
the accumulator in accordance with the weight of its plates. The mode of working
this arrangement or method is as follows:-
3"
Both the retracting spring p and the resistance of the electro-magnet h are regulated
in such manner that the force of attraction of the electro-magnet for its armature is
less than the mechanical force opposed by the retracting spring, so long as the
difference of potential at poles F is that which corresponds to the degree of saturation
required in the cell. When the proper degree of saturation is effected-which occurs
when the current, passing through the cell, operates only to produce gases which the

page_text: m,
plates do not take up-it is a well known fact that, owing to the presence of said
gases, the difference of potential between the poles Frises to 2.5 volts. or thereabouts,
and, by reason of this rise, the current circulating in the coil of the electro-magnet h,
which current, throughout charging, is only a small fraction of an ampère, increases
in intensity, by means of which the strength of the electro-magnet becomes also
increased and attracts the armature k. Then, by the closing of the circuit j k r l
the whole charging current passes by the resistance coil r, which is suitably graduated.
By this means the production of gases ceases, and the accumulator does not become
overcharged. By this new method and arrangement the charging can be continued
with impunity until the most backward cells are saturated and all are equalised. When
the action of the charging current has ceased, the difference of potential 2.5 volts.,
sustained by said current rapidly decreases, as is well known; and, in consequence of
this, the force of the electro-magnet is again lessened the armature k is pulled by
the retracting spring p, the shunt circuit is again broken at k and all the accumulators
become, once more, automatically and simultaneously placed in open circuit, the shunt
circuits of the electro-magnets alone remaining closed until these are also broken by
operating the plugs . The screw which regulates the tension of the retracting spring
may be graduated or gauged, so that, by this medium, the volts. and decimals thereof
may be measured during the charge, (because the decimals of volts., varying in the
different degrees of the charge, the force of the electro-magnet varies also) and thus
special volt-metres for observing the state of the charging are not required.
:
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. The herein described accumulator plates and the method of manufacturing the
same by which they are made to possess greater rigidity, duration and capacity and
are adapted to prevent the falling off of the active material or paste with which they
are coated or filled, said plates being composed of a skeleton body or support of lead
only, or of any other suitable metal or alloy of which lead may or may not form part,
substantially as described.
2. The method of soldering the plates to the connecting cross bars, and the latter
to the poles, without employing any solder but the metal itself, or the alloy, composing
the plates, substantially as described.
3. In an electric accumulator, the employment of an hermetically closed accumulator
case provided with one or more tubes and openings in the lid for the eduction of the
gases generated in charging the accumulator whereby the accumulation of the said
gases in the said case, or their diffusion through the atmosphere of the place where
the accumulator is located, is prevented, substantially as described and shown.
4. In a battery of electric accumulators, the method of and apparatus for preventing
the saturated elements of the battery from being overcharged, and allowing the charge
to be continued uninterruptedly until the saturation of the least charged elements has
been accomplished, which arrangement can be also used to measure the difference of
potential of each element at any moment, substantially as described.
Dated this 15th day of July 1890.
WM. P. THOMPSON & Co.,
Agents for the Applicant.