Improvements in the Automatic Electrical Distribution and Charge of Secondary Batteries.
Year: 1886

page_text: Date of Application, 2nd Apr., 1886.
Complete Left, 2nd Feb., 1887.
Complete Accepted, 29th Mar., 1887.
Improvements in the Automatic Electrical Distribution and
Charge of Secondary Batteries.
I, FRANK KING, of 38 Chesilton Road, Fulham, in the County of Middlesex,
Electrical Engineer, do hereby declare the nature of this invention to be as follows :-
My invention relates to a combination of apparatus and circuits whereby the charge
or discharge of secondary batteries is automatically accomplished at the proper time,
without interruption of the charging or discharging circuits, and whereby the
charging current, which may be of high tension, is prevented from reaching the
distributing mains, whilst a constant supply of electricity is maintained therein.
In carrying out my invention I employ a duplicate or more paired sets of
secondary batteries, their action of charge and discharge being alternate, except
where, on occasion, both sets of batteries may discharge into the distributing mains
together, as hereinafter more fully described. To each of these sets of batteries I
attach such a well known apparatus as a rocking switch, whose function is the
transposition of the connections of the batteries from "series" to "parallel" or
vice versa, and by the movement of which, at the same time, the batteries are placed
in the charging or distributing circuits respectively.
The said rocking switches may be operated by an electro-magnet and a counter
balance weight or equivalently by any electrical motor by reverse currents.
To each set of secondary batteries I attach some well known apparatus for
indicating either the condition of charge or completion of charge of the said batteries.
The apparatus may be either hydrometers, acidometers or such like devices, dependent
upon the specific gravity or of the electrolyte of the cells, or it may be an apparatus
dependent upon the pressure of the gas evolved from a battery cell when the electrode
or electrodes have been charged to their full capacity.
I make this apparatus actuate contacts and complete circuits to control electro-
magnets or other electro-motor device for moving the rocker or movable portion of
the aforesaid rocking or transposing switches into the desired positions.

page_text: In each of the circuits, which control the said electro magnets or other electro
motor device for moving the said movable portions of the said rocking or transposing
switches, I place a relay magnet, the armature of which carries a contact piece or
pieces, and a balance weight, which closes the said contacts by gravity when the electro
magnet of the relay ceases to act. One of the said contact pieces on the armature of
the relay magnet closes the circuit around the electro-magnet of the relay of the other
set of batteries, and through the electro-magnets or other electro motor device of the
rocking switch of the set of batteries, with which it is associated.
I conveniently construct the above "charge-indicator "which depends on the
pressure of the gas evolved from the cells, of a tube of insulating material with two
contact pieces, capable of being electrically united by means of a cylinder or globule
of mercury, and I incline the said tube so that the globule of mercury shall fall by
gravity on the contact pieces aforesaid. I also place another cylinder or globule of
mercury between the gas which is evolved from the cell, and the contact piece of the
tube (an air cushion being between the two globules) so that the cell gases, which
may be explosive, cannot reach the contacts, and so cannot be fired by the spark
produced at the moment of rupture of the circuit; and between the latter globule
or cylinder of mercury and the battery cell, I make an aperture in the tube, and close
this said aperture by a valve or stopper, actuated by a relay magnet and its armature
as hereinafter described.
When I use this form of "charge-indicator" I insert a galvanometer of high
resistance or such like potential indicator in the charging or distributing circuit of
each of the sets of batteries, and I make the movable portion of such apparatus
complete the circuit through the relay above mentioned as actuating the valve or
stopper of the "charge-indicator" when the potential at the terminals of the battery
or at the distributing mains has fallen to nearly the minimum amount permissible.
If now it is supposed that both sets of batteries are fully charged, and the gas
"charge-indicators are charged with gas, preventing the mercury globule from
closing the indicator circuit, I arrange that one of the aforesaid galvanometers closes
its contact as the potential falls considerably before the other thus completing the
circuit through the "charge indicator" relay of that set of batteries, the said relay
lifting the valve relieves the pressure of the gas in the "charge indicator," and thus
allows the globule of mercury to fall and complete the circuit through the electro
magnet or other electro motor device for actuating the rocker or movable part of the
rocking or transposing switch of that set of batteries to which the said galvanometer
is attached and also through the before mentioned rocker relay magnet, the armature
of which breaks the circuit through the electro magnets or other electro motor
device operating the movable portion of the other rocking or transposing switch and
the rocker or like part is thus rendered immovable."
One set of batteries is thus placed in the circuit of charge whilst the other set
remains as it were locked in the circuit of supply, and in connection with the
distributing mains.
The aforesaid potential indicator which set up the above described transposition of
one set of the batteries into the charging circuit, is thus brought into the said
charging circuit itself and the original contact on the said galvanometer is broken by
the rise in the electro motive force from the charging circuit actuating the movable
portion of the said galvanometer. The said valve in the "charge-indicator" thus
falls again on to its seat by gravity, being then ready for action on the further
generation of gas when that set of batteries is fully charged.
When the charge of the said batteries is completed the "charge-indicator" breaks
the circuit of the electro magnet or other electro motor device operating and holding
the rocking switch, by which the said batteries are maintained in the charge circuit.
The rocking switch, thus released, falls by gravity, or other electro motor device may
be reversed by a reverse current and breaks the connection between the said battery
and the charging main, and immediately connects the battery to the distributing main.
Simultaneously with the said movement of the rocking switch, the rocker relay
circuit is broken, which allows the said relay armature to fall and to complete

page_text: the circuit through the electro magnet or other electro motor device operating the
other rocking switch, and through the other rocker relay, throwing the other batteries
into the charging circuit.
When the charge of the second set of batteries is completed, the charge indicating
device, as before described, will break the circuit through the electro maguet or other
electro motor device of its rocking switch, and put the second set of batteries also on
to the distributing mains.
Both sets of batteries are then in supply together, provided that the current energy
in the first set of batteries is not exhausted. When the latter occurs, the above series
of actions are repeated indefinitely.
When both sets of batteries are in supply together, the armatures of the rocker
relays having then both fallen by gravity, make jointly another shunt circuit by
second contact pieces on the said armatures from any point on the distributing
mains or batteries which, operating a bye-pass relay, connects the charging mains
direct, through a suitable resistance to prevent sparking, and then short circuits the
said resistance.
When I use such charge indicating devices as a hydrometer, acidometer, or the
like, I may dispense with the before described potential indicator, and merely make.
the hydrometer or like device actuate a contact at each end of its stroke, so that the
action produced by the contact made at one end of the stroke of the hydrometer is
reversed by the effect of the contact made at the other end of the stroke.
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicant.

page_text: Improvements in the Automatic Electrical Distribution and
Charge of Secondary Batteries.
I, FRANK KING of 38 Chesilton Road Fulham in the County of Middlesex Electrical
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:
My Invention relates to a combination of apparatus and circuits whereby the charge
and discharge of Secondary batteries are automatically accomplished at the proper
times without interruption of the charging or discharging circuits and whereby the
charging current may be of high tension as it is prevented from reaching the
listributing mains a constant supply of electricity being maintained in such mains.
In carrying out my Invention I employ two or more Secondary batteries or sets of
Secondary batteries, the action of charge and discharge of the batteries or sets of
batteries alternating with each other except where on occasion both or all of the
batteries or sets of batteries may discharge into the distributing mains together as
hereinafter more fully described. Each of these batteries or sets of batteries I connect.
with an apparatus whose function is the transposition of the connections of the batteries
from "series" to "parallel " or vice versa and by the movement of which at the same
time the batteries are placed in the charging or distributing circuits respectively. This
apparatus may be a rocking switch of ordinary construction.
These rocking switches may be operated by an electro-magnet and a counter-balance
weight or equivalently by any electrical motor by reverse currents.
To each secondary battery or set of secondary batteries I attach an apparatus for
indicating either the condition or completion of charge of the batteries. This apparatus
may be of any ordinary or known kind, for example, it may consist of hydrometers,
acidometers or such like devices dependent upon the specific gravity of the electrolyte
of the cells or it may be an apparatus dependent on the pressure of the gas evolved
from a battery cell when the Electrode or Electrodes have been charged to their full
capacity. This apparatus is caused to actuate contacts to complete circuits controlling
Electro-magnets or other Electro-motor devices for moving the rocker or moveable
portion of the aforesaid rocking or transposing switches into the desired positions.
In each of the circuits which control the said electro-magnets or other electro-motor
device for actuating the moveable portions of the rocking or transposing switches, I
place a relay magnet, the armature of which carries a contact piece or pieces and a
balance weight which closes the said contacts by gravity when the Electro-magnet of
the relay ceases to act. One of the said contact pieces ou the armature of each of the
relay magnets closes the circuit around the Electro magnet of the relay of the other
set of batteries and through the Electro-magnets or other Electro-motor device of the
rocking switch of the set of batteries with which it is associated.
The "charge indicator" which depends on the pressure of the Gas evolved in the
battery cells may consist of a tube of insulated material and two contact pieces capable

page_text: of being electrically united by means of a cylinder or globule of mercury placed within
an inclined tube of insulating material so that the said cylinder or globule shall fall by
gravity on to the contact pieces aforesaid. I also place in the said tube another
cylinder or globule of mercury between the chamber containing the Gas which is
evolved and the first mentioned contact cylinder or Globule so that an air cushion will
be provided between the two cylinders or globules which will prevent the cell gases
(which may be explosive) from reaching the contact cylinder or globule so that they
cannot be fired by the spark produced at the moment of rupture of the circuit and
between the latter cylinder or globule of mercury and the battery cell I make an
aperture in the insulated tube and close the said aperture by a valve or stopper carried
by or actuated from the armature of a relay magnet as hereinafter described.
When I employ this form of charge indicator I insert in the charging or distributing
circuit of each of the sets of batteries a galvanometer of high resistance or such like
potential indicator and I make the moveable portion of such apparatus complete, the
circuit through the relay above mentioned for actuating the valve or stopper of the
charge indicator when the potential at the terminals of the battery or at the distributing
mains has fallen to nearly the minimum amount permissable.
Let it be supposed that both batteries or sets of batteries are fully charged and the
gas charge indicators are charged with gas and the mercury cylinder or globule
prevented from closing the rocking switch and contact relay circuits I arrange that
one of the aforesaid galvanometers or potential indicators closes its contact as the
potential falls so as to complete the circuit through the "charge" indicator, relay of
that battery or set of batteries considerably before the other galvanometer closes its
contact, the said relay lifting the valve and relieving the pressure of the gas in the gas
charge indicator and thus allowing the cylinder or globule of mercury to descend and
complete the circuit through the electro magnet or other electro-motor device for
actuating the rocker or moveable part of the rocking or transposing switch of that set
of batteries to which the said galvanometer is attached and also through the before
mentioned rocker relay magnet the armature of which breaks the circuit through the
Electro-magnets or other Electro-motor device operating the moveable portion of the
other rocking switch it being thus rendered immoveable.
One battery or set of batteries is thus placed in the circuit of charge whilst the other
remains in the circuit of supply and in connection with the distributing mains.
The aforesaid potential indicator which set up the above described transposition of
one battery or set of batteries into the charging circuit is thus brought into the said
charging circuit itself and the original contact on the said galvanometer is broken
by the rise in the Electro-motive force from the charging circuit actuating the
moveable portion of the said Galvanometer. The said valve in the "charge indicator
thus falls again on to its seat by gravity being then ready for action on the further
generation of gas when that battery or set of batteries is fully charged.
23
When the charge of the said battery or set of batteries is completed the "charge
indicator breaks the circuit of the electro magnet or other electro motor device
operating and holding the rocking switch by which the said battery or set of
batteries is maintained in the charging circuit. The rocking switch thus released
falls by gravity (or the other electro motor device may be reversed by a reverse
current) and breaks the connection between the said battery or set of batteries and
the charging circuit and immediately connects the said battery or set of batteries to
the distributing main.
Simultaneously with the said movement of the rocking switch the rocker relay
circuit is broken which allows the said relay armature to fall and to complete the
circuit through the electro magnet or other electro motor device operating the other
rocking switch and through the other rocker relay throwing the other battery or set
of batteries into the charging circuit. When the charge of the second battery or set
of batteries is completed the charge indicating device as before described will break
the circuit through the electro magnet or other electro motor device of its rocking
switch and put the second battery or set of batteries also on the distributing main.
Both batteries are sets of batteries are then in supply together provided that the

page_text: current energy in the first battery or sets of batteries is not exhausted. When
however the exhaustion occurs the above series of actions will be repeated indefinitely.
When both batteries or sets of batteries are in supply together the armatures of
both the rocker relays having then both fallen by gravity make jointly another shunt
circuit by second contact pieces on the said armatures from any point on the
distributing main or batteries which operating a bye pass relay connects the charging
circuits direct through a suitable resistance to prevent sparking and then short circuits
the said resistance.
When I use such charge indicating device as a hydrometer acidometer or the like
I may dispense with the before described potential indicator and merely make the
hydrometer for like device actuate a contact at each end of its stroke so that the
action produced by the contact made at one end of the stroke of the hydrometer or
acidometer or the like is reversed by the effect of the contact made at the outer end
of the stroke.
In order that my Invention may be clearly understood I will explain with reference
to the accompanying drawings means whereby the same may be carried into practical
effect. I premise however that I do not limit myself to the precise details which I
have illustrated as they may be varied without departing from the nature of my
Invention.
Figure 1 of the accompanying drawings represents diagrammatically one combi-
nation or arrangement of apparatus and circuits according to my Invention which I
will describe as applied to two sets of batteries from which its general application
will be understood.
Figure 2 illustrates a modification as hereinafter explained.
Referring to Figure 1 A A' are oscillating or rocking switches each electrically con-
nected to a separate set of batteries one cell of each of the sets of batteries being also shewn
at B and B¹ for the more clear delineation of the circuits. The oscillating or rocking
lever of each of the switches is fitted to turn on pivots band is operated by an electro
magnet c and a counter weight at to so as to make contacts to complete the circuit
alternately with the charging and the discharging mains as hereinafter described―The
charging main C C and the discharging main D D' are connected to the oscillating or
rocking switches A A' as shewn the positive lead from the dynamo-electric machine being
connected to the two switches A A' at d d' respectively and the negative lead of the said
charging main being connected to the said switches at e e¹ whilst the positive lead of the
discharging main is connected with the said switches A A' respectively at ff¹ and the
negative lead of the said discharging main is connected to the said switches at g g¹ respec-
tively E E are gas charge indicators for indicating when the batteries are fully charged
they being also employed to actuate contacts for completing and breaking the circuits
which control the actuation of the oscillating or rocking switches A A-In these circuits
are arranged relay magnets F F the armatures of each of which are provided with two
contact pieces ik and k³ respectively and a counter balance weight 11' respectively
for opening and closing the circuits through the electro magnetic devices which actuate
the rocking levers of the switches A A'-FF are potential indicators or galvanometers
of high resistance inserted in the circuits of the batteries at the rocking or transposing
switches and G is a bye pass relay for connecting the leads of the charging main
through a resistance coil G or through a carbon block G² or both to prevent dangerous
sparking when the current is suddenly diverted.
I will now describe the combined apparatus for which purpose let it be supposed
that the set of batteries in connection with the oscillating or rocking switch A is
discharging and the set of batteries in connection with the rocking switch A¹ is
charging. Under these conditions the switch levers a and a¹ will be in the position
shown and the positive current from the dynamo passing through the lead C will enter
the set of Batteries in connection with the switch A¹ at the point d and pass through
the cells of these batteries and thence by the lead C₁ back to the dynamo-Or instead
of passing directly back to the dynamo the current from the dynamo may if desired
be made to pass through one or more other sets of batteries before returning to the
dynamio.

page_text: When the set of batteries in. connection with the switch A' is fully charged, gas
evolved from the battery plate or plates will enter the chamber of the cell B₁ and pass
into the tube m¹ of the gas charge indicator E¹ and by its pressure will cause the
mercury globules n' o' to rise up the inclined portion of the said tube m¹ the Globule o¹
moving out of contact with the contact pieces p¹ q' thereby breaking the circuit which
had been exciting the electro magnet c' of the switch A' and also of the relay magnet F.
The switch lever a' will consequently fall over or rock on its pivots under the action
of its counter balance weight and make the contacts to put the battery connected with
the switch A' into circuit with the discharging main D D¹. The circuit through the
relay magnet F having also been broken the armature thereof will be released and will
by the counterweight 7 turn on its centre and make contacts at i and k.
The potential in the discharging batteries in connection with the switch A having
previously decreased to the limit allowed the current passing through the magnet of
the potential indicator or galvanometer F as indicated by the arrows 1 will not be
sufficiently strong to attract the armature against the counterbalance which will
consequently cause the contact end g² of the said armature to fall and make contact
with the two contact pieces h. A current will now pass from the positive lead D of
the discharging main as shewn by the arrows 2 through the contacts h and g to the
magnet of the gas charge indicator E and back to the lead D¹ of the discharging main
thus completing a circuit which will cause the armature of the gas charge indicator
magnet E to be attracted against the weight of the counterbalances and raise a valve r
from its seat in an opening in the tube m so as to allow the gas contained in the said
tube to escape whereupon the mercury globules n and o in the tube m will now fall by
gravity into the position shewn and thus make contact with the contact pieces pand
A current will then pass from the batteries in connection with the switch A through
the contact of the relay magnet F which had fallen when the charge to the batteries
connected to the switch A' was completed, as shewn by the arrows 3 and through the
contacts p og to the electro magnet c of the switch A thereby attracting the lever a
causing it to turn on its pivots b and bringing the batteries in connection therewith
in the charging main circuit and the current passing on to the relay magnet F¹ the
armature thereof will be attracted and the contacts at k¹ thereby broken the current
passing thence back to the batteries to complete the circuit.
When the batteries in connection with the switch A is introduced into the charging
circuit as above described the electro motive force at the potential indicator I will
rise and its magnet will accordingly attract the armature against the counterbalance
weight g and the circuit through the magnet of the gas charge indicator E will be
broken at whereupon the armature of the said magnet will by the weights close
the valve in the tube in in readiness for action in the evolution of gas from the battery
plate or plates connected with the gas charge indicator E. When the charge to the
batteries in connection with the switch A is completed, the gas evolved from the plate
or plates in the chamber B will enter the tube m and by its pressure will force the
mercury globule out of contact with the contact pieces pq and thus break the circuit
through the magnet in connection with the switch A the lever of which switch will
then under the action of its counter balance weight fall over and place the batteries in
connection therewith again in the circuit of the discharging mains D D'. If the
electro motive force from the batteries attached to the switch A which have ineanwhile
been in the discharge circuit as described has not fallen sufficiently to cause the
magnet of the potential indicator F³ to release its armature from the contacts i¹¹ the
two sets of batteries will be together in the discharging main. When this is the case
a current from the discharging main will pass through the contact ¹ of the relay
magnet F¹ (as indicated by the arrows 4) to the coil of the bye pass G thereby
attracting the armature T bringing the end thereof into the mercury cup
t¹ and by
its continued movement also afterwards bringing a contact piece u into contact with a
block G which connects the leads C and C of the charging mains first by a circuit
through the resistance G' as shown by the arrows 5 and afterwards through the short
circuit past the (resistance G¹) made by the carbon block G and contact u thereby

page_text: preventing dangerous sparking and maintaining a constant circuit in the charging
leads.
When the batteries in connection with the switch A¹ are discharging and exhausted
to the predetermined limit the electro motive force will be insufficient to actuate the
movable portion of the potential indicator or galvanometer F³ the said movable portion
or armature will consequently be released and will make contact between the end g³
thereof and the contacts and thereby establish a circuit from the discharging
main through the magnet of the gas charge indicator E as shewn by the arrows 7
which magnet being thus excited will attract the armature thereof against the
counter balance weights raising the valve from the opening in the tube m¹
and allowing the gas contained in the said tube to escape and admit of the
globulesno (which had been raised in the tube by the pressure of gas
evolved from the plate or plates in the-chamber B₁ when the batteries were fully
charged) to descend and make contact with the contact pieces p² 7. The set of
batteries attached to switch A will then again come into the charging circuit. If
however while this set of batteries is charging the electro-motive force at the distributing
main falls to the minimum permissible, the lever g2 of the potential indicator F2 will
fall, and completing the circuit indicated by the arrows 2 to the gas charge indicator E
will actuate its armature and allow the mercury globules no to fall, and the mercury
globule o to make contact at p g. The circuit of the electro magnetic device c and the
rocking switch A will however not be complete, because the magnet of the relay F is
holding its armature and consequently maintaining open the circuit at the contacts i
and. It will be seen from the foregoing description that the sets of batteries
respectively in connection with the two rocking switches A and A¹ are alternately and
automatically brought into the circuit of the charging main to be recharged without
interruption of the charging or discharging circuits and the charging current is
prevented from reaching the distributing main whilst at the same time a constant
supply of electricity is maintained in the discharging mains. Figure 2 represents a
combination of apparatus in which instead of the gas charge indicators E E¹ herein-
before described with reference to Figure 1 I employ hydrometers or acidometers or
the like E E' (which I will refer to as hydrometers) the floats of which are elevated
more or less according to the specific gravity of the electrolyte in the cells of the
batteries and I dispense with the indicators F3 hereinbefore described, A A¹ are
the two rocking switches which are similar to those herein before described with
reference to Figure 1, that marked A being represented in the position in which the
set of batteries connected therewith is in the discharging main circuit and that
marked A' being in the position in which the set of batteries connected therewith is
in the charging main, CC are respectively the positive lead and the negative lead of
the charging main and D D¹ are respectively the positive lead and the negative lead
of the discharging or distributing main. The connections of these mains with the
switches A A¹ are the same as described with reference to Figure 1.
The float of each of the hydrometers E E' is connected by a link y to a double
armed lever R R¹ the outer ends of the arms being arranged to dip alternately into
two mercury cups SP and S₁ P' according as the hydrometer float is raised or lowered
the arms being centred to a standard as shewn. The stem of each of the floats passes
through a guide a² and through a hole in the core of a solenoid L L for retaining
the float in its elevated position as hereinafter described.
C
F F are two electro magnets arranged to operate alternately a single armature g so
as to bring it into contact alternately with contact pieces ik and for the purpose
of maintaining the current in the desired direction while the batteries are in the
discharging or charging circuits.
Let it be supposed (for example) that the set of batteries in connection with the
rocking switch A is at about the predetermined maximum allowable point of exhaustion
and the set of batteries in connection with the other switch A' is about being fully
charged the lever a¹ of this latter switch maintaining this latter set of batteries in the
charging circuit by a current passing from the distributing main (as indicated by

page_text: the arrows 9) through the solenoid L to the electro magnet C' and then passing by the
contacts to the electro magnet F¹ so as to maintain the armature g in the position
shewn and completing the circuit back to the distributing main as shewn by the
arrows 9.
The set of batteries attached to the switch A¹ is now being charged and the set of
batteries attached to the switch A is in the discharging circuit and this position is
maintained by the action of the solenoid L which by the passage of the current around
its coils draws or attracts its core and so prevents the possible movement of the
hydrometer bulb and stem in the cell E and however low the discharge of the set of
batteries attached to the rocking switch A has proceeded it is impossible for that set
of batteries to be removed from the discharging circuit until the set of batteries
attached to the rocking switch A has been fully charged and the free hydrometer
bulb in the cell E¹ has risen a sufficient distance to break the circuit at the mercury
cup as indicated by arrows 9.
When however the charge to the set of batteries attached to the rocking switch A¹
is completed the circuit indicated by the arrows 9 will be broken as before stated at
the mercury cup P¹ the armature g will be released from the magnet F¹ and will fall
back to a neutral position the armature of the lever a¹ of the rocking switch A¹ will be
released from the magnet c¹ under the action of its counterbalance weight and the set
of batteries will thus be transferred from the charging circuit to the discharging main
and at the same time the core of the solenoid L will release the hydrometer bulb of
the cell E and the said bulb will fall in the liquid bringing the lever attached thereto
into the mercury cup P. A circuit will now be made in the direction of arrows 10
from a point on the distributing mains through the magnet F (thereby attracting the
armature g) thence through the electro magnet or other electric device C for moving
the rocker bar a of the switch A, thence through the solenoid L' and back to the
distributing main. The solenoid I will attract its core and grip the stem of the
hydrometer bulb of the cell E¹ thus maintaining the battery attached to the rocking
switch A¹ in the distributing main.
The charge to the set of batteries attached to rocking switch A will now proceed
and the hydrometer bulb and stem attached to the cell E will accordingly commence
to rise when the charge to this set of batteries is completed the circuit indicated by
arrows 10 will be broken at the mercury cup P of the cell E and the magnet F will
release its armature g which will then fall to the neutral position, the electro magnet
device e will release the lever a and the set of batteries connected with the switch A
will be thus transferred by the movement of the lever a into the circuit of the dis-
tributing main. Both sets of batteries will now be supplying current to the distributing
main and the levers R R will have their ends in contact with the mercury cups S S¹
A current will then pass from the distributing main at the switch A as shewn by the
arrows 10, along the lever R through the mercury cup at S thence as indicated by
arrows 11 to the bye-pass magnet T and through the mercury cup S₁ back to the
opposite pole of the distributing main as shewn by the arrows 9.
The magnet or
solenoid T being thus excited will attract its armature and cause its end t to make
contact with the mercury cup t¹ and on the completion of the stroke of the armature
the carbon end u thereof will make contact with a carbon block at G' thus connecting
the charging main CC (in like manner to that described with reference to Figure 1)
first through a resistance and afterwards short circuiting that resistance and maintaining
the continuity of the charging circuit.
When one of the sets of batteries attached to the rocking switches A A¹ has become
exhausted to the predetermined limit the hydrometer bulb in connection with that set
of batteries will fall and cause the lever connected therewith to be inserted in the
mercury cup P or P₁ as the case may be and the circuit will then be completed, as
before described and effect the locking of the other set of batteries in the position
required by the maintenance of one set of batteries in the circuit of the discharging
main and the before mentioned operation will be repeated.
R

page_text: Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is:
First A combination of apparatus for automatically charging and discharging two
or more secondary batteries or sets of secondary batteries at the proper times without
interrupting the charging and discharging circuits substantially as herein before
described.
Second In apparatus for effecting automatically the charging and discharging of
two or more secondary batteries or sets of secondary batteries the combination there-
with of the apparatus for indicating the completion of the charge of the said batteries
the said indicating apparatus being arranged to operate substantially in the manner
herein before described and illustrated in the accompanying drawings.
Third In apparatus for alternately and automatically charging two or more
secondary batteries or sets of secondary batteries the combination of a bye pass relay
and resistance in connection with the charging main, and the relays F F and their
contacts substantially as and for the purpose hereinbefore described with reference
to the accompanying drawings.
Fourth In apparatus for alternately and automatically discharging one or both of
two or more secondary batteries or sets of secondary batteries the combination
of rocking switches A A', charge indicators E E', potential indicators F F³, relay
magnets and contacts F F¹, and the circuits connecting the same substantially as
hereinbefore described and illustrated by the accompanying drawings.
Fifth The general constructions combinations and arrangements of apparatus for
automatically charging and discharging two or more secondary batteries or sets of
secondary batteries without interruption of the distributing main circuit as hereinbefore
described and illustrated respectively in Figure 1 and Figure 2 of the accompanying
drawings.
Thated this on
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