Improved Means for Controlling the Discharge of Electric Storage Batteries.
Year: 1899

page_text: Date of Application, 1st Apr., 1899-Accepted, 15th July, 1899
COMPLETE SPECIFICATION.
Improved Means for Controlling the Discharge of Electric Storage
Batteries.
A communication from abroad by THE POPE MANUFACTURING COMPANY (In-
corporated), of Hartford, Connecticut, United States of America.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56, Chancery Lane, in the County of
Middlesex, Fellow of the Chartered Institute of Patent Agents, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
1
The practical use of storage batteries has developed the fact that they can be
used with safety under varying conditions of load until the potential or voltage
falls permanently below a certain point, and that further exhaustion of the
batteries beyond this point occasions rapid deterioration of the batteries by reason
of the destruction of the plates so that they are thereafter incapable of being re-
charged to the full amount which was before possible. When such batteries are
under the constant supervision of experts they can be disconnected before the
exhaustion is carried to the danger point, but when they are not subject to such
supervision but are under the control of non-experts, as is the case when storage
batteries are employed to supply the motive power of motor vehicles intended for
private use, it frequently happens that the batteries are exhausted beyond the
danger or minimum point, thereby entailing much inconvenience and expense in
the substitution of new batteries. It is the object of this invention to guard
against such injurious exhaustion of the batteries even though the manage-
ment of the batteries is in the hands of non-experts or
to make such exhaustion, if it takes place, the result of a wilful and deliberate
at any rate
action upon the part of the operator, so that the responsibility for such ex-
haustion shall be placed where it belongs. It will be evident that the general.
object in view can be secured in somewhat different ways, as by causing the
batteries to indicate their approach to a dangerous condition by a visual signal
which will be easily discerned and readily understood by inexpert operators, or by
an audible signal or alarm, or by an automatic disconnection or cutting out of such
batteries when they approach a dangerous condition, but whatever may be the
particular means employed, it will be understood that all of such means are.
actuated by or are dependent for their operation upon a decrease in the voltage
or potential of the batteries whenever, under otherwise normal conditions, it
alls below a predetermined minimum. Reference is here made to a decrease in
potential when the conditions are otherwise normal, because the batteries are not
njuriously exhausted when the voltage or potential is reduced for a short time
nly below the danger point or predetermined minimum, as when a heavy load is
emporarily put upon the batteries in the case of a motor vehicle mounting a steep
rade. Under such conditions the amperage of the batteries furnishes a basis of.
neans of determination whereby the signal or cut-out becomes ineffective or
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page_text: inoperative. The embodiment of the invention in an automatic cut-out will first
be described, and thereafter will be described the embodiments of the invention
in the form of 'signalling devices, these being preferred because, while calling the
attention to the operator unmistakably to the condition of the batteries and
placing upon him a responsibility for their further use, they also leave the 5
operator free to exercise his judgment as to the necessity for further use of the
batteries.
Figure 1 is a diagrammatic and partly sectional view of one form of the device
for preventing exhaustion of the battery.
Figures 2 and 3 are similar views of different forms of such devices.
Figure 4 is a plan view of a combined ammeter and voltmeter which illustrates
one embodiment of the invention.
Figure 5 is a transverse section of the construction shown in Figure 4.
Figure 6 is a view similar to Figure 5, but showing a slightly different
arrangement.
Figure 7 is a plan view of another form of visual signalling device, with part
of the top removed, interior details being omitted.
Figures 8 and 9 are plan views of other forms of visual signalling devices.
Figure 10 is a diagrammatic view illustrating the embodiment of the invention
in an audible signalling device or alarm.
".
-In the arrangement represented in Figure 1, the battery or other source of
electro-motive force indicated at a" as composed of several cells or boxes, is
represented as connected in circuit with a motor through a switch or cut-out b.
The latter may be of any ordinary or preferred form and is shown as comprising
two terminals and a finger or bridge piece which is movable to open the switch
or cut-out. This particular arrangement of the switch or cut-out is shown merely
for convenience and any other suitable arrangement may be substituted. The
switch or cut-out is under the control of a device which is operated, or the.
operation of which is determined by the potential of the current passing through
the same. Any suitable form of electrically operated device may be employed,
but as shown in Figures 1 and 2 it consists of a solenoid d. which is so wound
as to respond to differences in potential of the current which passes through it. As
here shown it is shunt wound with small, wire and its core e is mechanically
connected with the movable member of, the switch or cut-out. The tendency of
this device is to move the core and therefore the movable member of the switch or
cut-out in a direction to keep the switch or cut-out closed, but the said movable
member of the said switch or cut-out is acted upon at the same time by means
which tend to move it in the opposite direction to open the switch, the force of
such means, however, being such that it is unable to overcome the force of the
controller so long as the voltage or potential of the current flowing through
the controller remains above the predetermined minimum or danger point.
As soon as the voltage or potential falls below this point, the force of the controller
is weakened and the movement of the switch under the influence of the opposing
means is permitted.
It will be obvious that so far as concerns the mere opening of the switch when
the voltage falls it is immaterial what form of means is employed to act upon the
movable member of the switch or cut-out in opposition to the controller & but
preferably, and especially with due regard to the attainment of the objects of the
invention, another electro-magnetic device f of a character similar to that of the
controller d is employed and in its most convenient form consists of a solenoid
wound in series in the main circuit with heavy wire so that its strength is
dependent upon and its operation is determined by the amperage of the current
which passes through it. As represented in this Figure 1 of the drawings the
device is axially in line with the controller and operates upon the common
core e.
It will now be understood that so long as the voltage of the batteries remains
above the predetermined minimum, the force of the controller d, which is
1

page_text: suitably wound for the purpose, at least balances if it does not exceed the force of
the oppositely acting device f, whereby the switch or cut-out is kept closed, but as
soon as the voltage falls below the predetermined minimum the strength of the
controller, is so far diminished as to permit the core e to be moved under the
influence of the solenoid f so as to open the switch or cut-out, the amperage of
the battery meanwhile remaining substantially normal.
If, however, the voltage is reduced momentarily by excessive drains on the
battery, the reduction will be coincident with an increase in the amperage which
naturally would cause the movement of the core e to the right in Figure 1-thereby
opening the cut-out or switch. The operation of the cut-out under such conditions
is undesirable and the increased amperage of the solenoid f is therefore taken
advantage of to.operate a lock in such a manner as to prevent movement of the
core and opening of the cut-out under these conditions. As shown the lock con-
sists of an armature g. supported in proximity to the end of the solenoid f by a
suitable. lever, the armature being normally held back by an adjusting spring
while the movement is limited by a stop. The core e is provided with a non-
magnetic extension which is formed with a notch with which the armature or
lock g engages. when it is moved by the influence of the solenoid.
Another similar. arrangement is shown in Figure 2 in which the two solenoids d
and fact upon separate cores i and k which are connected to a switch lever l. A
lock g co-operates with one of the cores k in the manner already described with
respect to the construction shown in Figure 1. The two cores are acted upon by
the two opposing solenoids d and f which are series wound in the main circuit
with heavy wire, the strength of the solenoid f being greater than the strength
of the solenoid d.. The strength of the solenoid f-is, however, over-balanced so
as to keep the switch or cut-out closed under normal condition by an additional
shunt coil m of fine wire which also acts upon the core so as to overbalance
the solenoid f under normal conditions. The coil m responds immediately to a
decrease in the. voltage so that the combined strength of the coil d and the coil m
becomes less than the strength of the coil f thus permitting the opening of
the cut-out or switch. It will be observed that the coil m operates as a controller
in the same manner as does the coil & shown in Figure 1.
In both of the constructions previously described as shown in Figures 1 and 2
the electro-magnetic devices act directly upon the switch lever to move the same,
but it will be readily understood that the same result can be secured by arranging
the switch lever or arm to be operated by independent means, such as a spring, but
subject to the control of electro-magnetic devices operating in substantially the
same manner as those already described. Such an arrangement is shown in
Figure 3 of the drawings in which the switch lever 7 is acted upon by a spring to
open the switch. A shunt wound magnet n, when the voltage is normal, holds
its armature o in such a position that an arm secured to said armature stands in
the path of the switch lever and prevents its movement, but when the armature
is released by the magnet the arm moves so as to release the switch lever and
permit it to be moved by its spring. A series wound magnet q, so long as the
amperage of the current does not fall below the normal, holds its armaturer in
such a position that an arms projecting therefrom stands in the path of a shoulder
on the armature o and prevents the movement of the armature which would release
the switch lever. If the amperage and the voltage both fall below the normal,
indicating permanent exhaustion of the battery, both armatures will be released,
the point of arms will drop below the shoulder of armature o and the latter, moved
by the pull of the magnet q which then overcomes the pull of the magnet n will
disengage the arm of the armature o from the switch lever.
As shown in the several figures of the drawings, the voltage, when all of the
elements of the battery are in circuit, will determine the operation of the cut-out,
but it is obviously possible to arrange the wiring in connection with the cut-out in
such manner that there may be one such cut-out for each of the boxes or elements
of the battery, or that the main circuit may be cut out when the voltage of any

page_text: one box or element reaches a predetermined minimum, or that one box alone may
be cut-out when the voltage of that box reaches the predetermined minimum,
such arrangments of the wiring, however, are not material to the present invention.
It will be observed that the arrangements shown herein are particularly adapted
for application to motor vehicles as they are not liable to be rendered inoperative by
jolts and jars to which they would be subjected when applied to such uses.
On
Referring now to Figures 4, 5 and 6 in which is illustrated one embodiment of
the invention in a visual signalling device, an ordinary ammeter needle t is
represented as having an enlargement or extension u near its axis, upon which is
formed the voltmeter scale v for an ordinary voltmeter needle w, mounted. at one
side of the ammeter needle. The plate or top of the combined ammeter and
voltmeter is slotted as at a so as to disclose the voltmeter scale when the ammeter
needle is in its normal position, that is to say, when the discharge of the batteries
is normal. As already indicated, it is only when the rate of discharge of the
batteries is normal that the decrease in the voltage should operate either to.
cut out the batteries, as described above, or to indicate to the operator a dangerous
condition. Therefore, when the ammeter needle is in its normal position the.
operator can tell by a glance at the voltmeter index, which is then visible, whether
the voltmeter needle indicates a safe or dangerous condition of the batteries.
the other hand, if the ammeter needle is not in normal position, the rate of dis-
charge being abnormal, the voltmeter scale will not be visible and the operator will
be informed by that fact that it is unnecessary for him to ascertain the position of
the voltmeter needle. In other words, it is necessary for the operator to examine
the device closely only at such times as the voltmeter scale is visible, and then
he will be informed at a glance, by the position of the voltmeter needle with respect
to the danger mark, as to the condition of the batteries. In the arrangement
shown in Figure 6 the voltmeter scale is carried below the ammeter needle ut,
and the ammeter needle is slotted so as to disclose the scale when the ammeter needle
is in normal position. When the scale is mounted on the ammeter needle it is
desirable that the voltmeter needle shall be of the same color as the main body of
the ammeter needle and of contrasting color with the scale, so that the voltmeter
needle shall be distinctly visible when the scale is in position and shall not be
visible at other times. The voltmeter scale may have a distinct danger mark,
or it may have one portion colored differently from the rest to indicate the danger
position of the neeille.
In the construction shown in Figure 7, in which is illustrated another embodi-
ment of the invention in a visual signal, the ammeter dial or scale is dispensed
with and the ammeter needle becomes an arm having connected therewith a
contact making arm y the function of which is to break the circuit of the voltmeter
whenever the amperage is greater or less than normal, the relative angular position
of the contact arm being adjustable by means of an adjusting screw as represented.
When the amperage is normal the voltmeter circuit is completed and the voltmeter
needle w will indicate upon the voltmeter scale the voltage of the current, thereby
informing the operator as to the condition of the batteries, but when the amperage
is abnormal the voltmeter circuit will be broken and the voltmeter needle will
drop. The scale may have a suitable danger mark properly placed or may be
colored or in any other way made to show clearly the danger position of the needle.
In this figure the voltmeter needle is shown without regard to the danger point.
In Figures 8 and 9 are shown forms of visual signalling devices which embody
the invention and differ from those just described in that there is no movable
scale and no device for breaking the circuit, but by means of which, the same
general result is produced. In Figure 8 the voltmeter and the ammeter are
arranged side by side with their scales in close proximity so that the eye of the
operator can glance readily from one to the other or see them both at the same
instant. The ammeter needle t is represented as standing a little off from its
normal position, which is indicated by the mark placed near it, and the voltmeter
needle wis represented as standing a short distance from the danger mark

page_text: Should the ammeter needle stand on or near the normal mark and the voltmeter
needle approach closely the danger mark, then the operator will be informed at a
glance that the batteries are exhausted to a dangerous degree, but if the ammeter
needle stands away from the normal mark then the operator need not consider the
position of the voltmeter needle. In the construction shown in Figure 9 the two
meters are mechanically separated but the two needles and w move through
substantially coincident arcs. The two needles may be wide and narrow respec-
tively or differently colored or otherwise distinguished from each other.
Separate scales for the two needles may be provided or one scale may be common
to both. The scale or scales may have the normal and danger points indicated by
special marks or different portions may be colored differently. In this case,
as in the others the voltage will be read when the ammeter needle stands upon the
mark and indicates that the amperage is normal. The danger mark for the
voltmeter needle, with a proper adjustment of the parts, may be located so as to
coincide with the normal amperage mark or to be upon the ammeter needle itself,
in which case, the registration of the two needles and the normal mark will
indicate to the operator that the condition of the batteries is dangerous. The
voltage danger mark might also, of course, be placed at any other point if the
parts are properly adjusted. In the last two forms described, as in the others, the
normal and danger points may be indicated in any suitable manner, as by a mark
or by different coloring, or by illumination, as by phosphorescent paint or other
suitable means, so that the instrument would be readable in the dark. The.
needles might also be illuminated. Different portions of the glass top or covering
of the instrument might be differently colored also.
In Figure 10 is indicated an embodiment of the invention in an audible signal
or alarm. The arrangement of the amperage and voltage solenoids in the circuit
will be readily understood in view of the previous description of the automatic
cut-out devices, but in this case there is added an ordinary electric bell z which
is included in a shunt circuit, as represented. This shunt circuit also includes two
switches 1 and 2 which are actuated or controlled respectively by the amperage
solenoid and the voltage solenoid. So long as there is no current on the system
both switches are closed, but under normal conditions the volt switch at 2 is
open, being kept open by a voltage anywhere above the danger point; the
ampere switch at 1 is normally closed, the amperage solenoid not having sufficient
power, when the amperage is normal, to open the switch and break the circuit.
Consequently, if the voltage falls below the danger point when other conditions
are normal the alarm circuit is closed and the alarm is given; but if, during the
drop of the voltage below the danger point, the amperage rises, then the ampere
switch will be open at the time when the volt switch is closed and the alarm circuit
will not be complete.
These various illustrations of the embodiment of the invention in signalling
devices have been described merely to enable the nature of the invention to be
clearly understood, and it will be obvious that various other forms might be
employed in place of those shown and described herein, whereby the fall of the
voltage under normal conditions shall operate to prevent or guard against the
further exhaustion of the batteries by a signal or by an automatic cutting out of
the batteries.
Having now particularly described and ascertained the nature of the said
invention, 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. As a means for guarding against or preventing the exhaustion of storage
batteries beyond the point of permanent injury, a device operated by a permanent
reduction in the voltage of the battery when the amperage is normal to indicate
the exhaustion of the battery to a dangerous point and a device operated by
abnormal amperage of the battery to offset or negative the action of the first named
device, substantially as shown and described.

page_text: 2. As a means for guarding against or preventing the exhaustion of storage
batteries beyond the point of permanent injury, an ammeter included in circuit
with the battery and having a mark to indicate a normal rate of discharge and a
voltmeter also included in circuit with the battery and having a mark located
with respect to the normal mark of the ammeter so that the relative voltage of the
battery under normal conditions shall be indicated clearly, substantially as shown
and described.
3. As a device for indicating at a glance the condition of a storage battery
when it approaches the point of dangerous exhaustion, an animeter having a
needle with the voltmeter scale formed thereon and visible through the top or
cover of the instrument only when the ammeter needle is in normal position, and a
voltmeter having its needle disposed so as to indicate the voltage upon said scale
when the same is visible, substantially as shown and described.
4. An automatic cut-out to prevent the exhaustion of secondary batteries in
motor vehicles, etc., below the point of permanent injury, such cut-out com-
prising an electro-magnetic device tending to open the cut-out, the operation of
said device being determined by the amperage of the current passing through, the
same, and an electro-magnetic controller acting in opposition to said device,,the
operation of said controller being determined by the potential of the current
passing through the same, whereby the cut-out is opened when such potential falls
below the normal, substantially as shown and described.
5. An automatic cut-out to prevent the exhaustion of secondary batteries in
motor vehicles, etc., below the point of permanent injury, such cut-out comprising
two solenoids acting in opposition upon the cut-out, one of said solenoids being
coarse-wound and tending to open said cut-out and the other of said solenoids
being fine-wound and tending to keep said cut-out closed but permitting the
other solenoid to open said cut-out when the potential of the current falls below the
normal, substantially as shown and described.
6. An automatic cut-out to prevent the exhaustion of secondary batteries in
motor vehicles, etc., below the point of permanent injury, such cut-out comprising
two solenoids acting in opposition upon the cut-out, one of said solenoids being
coarse-wound and tending to open said cut-out and the other of said solenoids
being fine-wound and tending to keep said cut-out closed but permitting the
other solenoid to open said cut-out when the potential of the current falls below
the normal, and a lock to prevent movement of said cut-out, substantially as shown
and described.
1 1000