Improved Apparatus for Indicating the Charge in a Secondary Battery.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improved Apparatus for Indicating the Charge in a Secondary
Battery.
We, FREDERICK WILLIAM COOKE, Electrical Engineer, Marlborough House,
Holly Road, Retford, Nottinghamshire and THOMAS IRELAND, Telegraph Engineer,
Babworth Road, Retford, Nottinghamshire, do hereby declare the nature of this
invention to be as follows:-
or the amount of
Our invention consists in improved apparatus for shewing the amount of
charge in an accumulator or secondary battery, so that at a glance an unskilled
attendant may estimate the number of light hours":
electrical energy it contains. The apparatus is constructed as follows:-We
employ an electromotor, which may be of any ordinary type, the field magnei
coils being in series with the charging circuit. The armature of this motor is
mounted upon a spindle, at the opposite end of which, or nearly so, is fitted a
loose sleeve carrying a soft iron ring or the like, which revolves in front of
the pole or poles of a fixed electro-magnet, having more than two poles if
required. The brushes conveying the current to the motor armature may be
coupled in series or in parallel with the coil or coils of the fixed electro-magnet,
the exciting current being taken from one, two, or more cells of the secondary
battery, or from some independent source. To regulate the motor so as to
correctly account for the loss of energy between charge and discharge, we em-
ploy a brake operated as follows:-The loose sleeve of the soft iron ring or its
equivalent upon the armature spindle is formed with a helical or inclined slot
which engages with a pin driven into, or similarly secured to the spindle. The
sleeve and the slot engaging with the pin, are so mounted and arranged upon
the armature spindle as that when the armature of the motor is running in the
direction due to a charging current the ring is, by means of its momentum and
the inter-action of the slot and pin, brought very near to the poles of the fixed
electro-magnet, thereby creating the greatest braking effect. When however the
battery is discharging, the ring armature is withdrawn by the reversal of motion.
We may modify the regulating mechanism just described by dispensing with
the sleeve, and making the ring armature occupy a fixed position on the spindle.
By automatically reducing the exciting current flowing in the coils of the fixed
electromagnet upon discharge, we obtain the required compensation. In order
that the vibration of the building or vehicle in or upon which this instrument may
be placed, may not interfere with the indications when not registering or running,
we attach to the armature spindle, or other moving part, a catch or stop, which
is released by the current passing through the instrument.
At any convenient point upon the armature spindle is cut or fitted a worm;

page_text: .
or other suitable device for actuating a wheel train, with pointer, index fingers,
or like, moving in front of a dial or dials, upon which may be painted, lettered
or engraved, such words as Full" Empty," the number of Lamp Hours,"
or equivalent terms, figures or devices easily apprehended by an unskilled
The operation of our invention will be readily understood:-During
the charging operation the number of revolutions of the motor are indicated
by the finger, pointers, or the like, which move in the forward direction. Upon
discharge the direction of motion being reversed, the index fingers travel back-
wards, thus shewing the amount of residual charge.
attendant.
Hotl 4h 19th day of March 1898
FRANCIS M. ROGERS,
Agent for Applicant, 21, Finsbury Pavement, London, E.C.
Improved Apparatus for Indicating the Charge in a Secondary
Battery.
We, FREDERICK WILLIAM COOKE, Electrical Engineer, Marlborough House,
Holly Road, Retford, Nottinghamshire and THOMAS IRELAND, Telegraph Engineer,
Babworth Road, Ketford, Nottinghamshire, 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:-
Our invention consists in improved apparatus for shewing the amount of
charge in an accumulator or secondary battery, so that at a glance an unskilled
attendant may estimate the number of "light hours"; or the amount of
electrical energy it contains. The apparatus is constructed as follows:-We
employ an electromotor, which may be of any ordinary type, the field magnet
coils being in series with the charging circuit. The armature of this motor is
mounted upon a spindle, at the opposite end of which, or nearly so, is fitted a
loose sleeve carrying a soft iron ring or the like, which revolves in front of
the pole or poles of a fixed electro-magnet, having more than two poles if
required. The brushes conveying current to the motor armature may be
coupled in series or in parallel with the coil or coils of the fixed electro-magnet,
the exciting current being taken from one, two, or more cells of the secondary
battery, or from some independent source. To regulate the motor so as to
correctly account for the loss of energy between charge and discharge, we em-
ploy a bake operated as follows: The loose sleeve of the soft iron ring or its
equivalent upon the armature spindle is formed with a helical or inclined slot
which engages with a pin driven into, or similarly secured, to the spindle. The
sleeve and the slot engaging with the pin, are so mounted and arranged upon
the armature spindle as that when the armature of the motor is running in the
direction due to a charging current the ring is, by means of its momentum and
the interaction of the slot and pin, brought very near to the poles of the fixed
electro-magnet, thereby creating the greatest braking effect. When however the
battery is discharging, the ring armature is withdrawn by the reversal of motion.
In order that the vibration of the building or vehicle in or upon which this
instrument may be placed, may not interfere with the indications when not
registering or running, we attach to the armature spindle, or other moving part
a catch or stop, which is released by the current passing through the instument.
At any convenient point upon the armature spindle is cut or fitted a worm;
or other suitable device for actuating a wheel train, with pointer, index fingers
or like, moving in front of a dial or dials, upon which may be painted, lettered

page_text: "
or engraved, such words as "Full," "Empty," the number of "Lamp Hours
or equivalent terms, figures or devices easily apprehended by an unskilled
attendant. The operation of our invention will be readily understood:-During
the charging operation the number of revolutions of the motor are indicated
by the finger, pointers, or the like, which move in the forward direction. Upon
discharge the direction of motion being reversed, the index fingers travel back-
wards, thus shewing the amount of residual charge.
We will now proceed to describe our invention more particularly by means
of the annexed drawing, in which:
Fig. 1. Is a front elevation, the dial and front of case or cover being removed.
Fig. 2. Is a side elevation.
Fig. 3. Is a front view of dial and case to reduced scale.
Fig. 4. Is a plan looking up, of electro-motor.
Fig. 5. Is a plan of magnetic brake.
Fig. 6. Is a diagram shewing the electrical connections.
In the drawing, 1 is the base plate formed of any suitable metal, such as
brass or the like. This is secured by screws 2 to the brackets 3, which support
the electro-motor 4 by screws 2 threaded into its soft iron pole pieces 5; the two
cores or legs of the field magnets 6 are stepped into these pole pieces at the lower
end, and preferably secured by grub screws 21, their upper ends being secured to
the yoke by set screws 21. Discs of vulcanised fibre or ebonite, or other
bobbins 8, replacing them, are forced on to each field magnet leg 6 which are
then wound with insulated wire 9 of suitable thickness, to safely carry the
charging current, and connected to the binding screw plates 10, insulated from
the frame as shewn by ebonite or like substance 10¹. The yoke 7 serves as a
support for the frame 1", which carries the regulating electro-magnet 11. An
armature 12 is mounted upon a spindle 13 stepped into the base of the instrument 1
and adjustably pivoted at its upper end as at 14 by a set screw 2111 Upon the
spindle is mounted at one end the commutator 15, fitted with brushes 10, insulated
by ebonite strips 10¹ from the pole piece, and connected in series with the brake
circuit. At the upper end of the spindle 13 is a loose sleeve 17, in which is
formed a helical slot 18. A pin 19 driven into the spindle engages with this slot
in the manner shewn. To this sleeve is attached preferably by means of
and
cruciform spider 21,
screws 2,
The
soft iron
21
ring 22.
sleeve and slot engaging with the pin 19 are so arranged upon the armature
spindle, as that when the armature of the motor is running in the direction due
to a charging current the ring 22 is, by its momentum and the interaction of
the pin and slot, brought very near to the poles 5 of the electro-magnet 11,
thereby creating its greatest braking effect. When, however, the secondary
battery 23 (See Fig. 6) is discharging, the ring 22 is withdrawn therefrom by
the reversal of the motion and the interaction of the slot and pin. The coils
of the electro-magnet, are suitably wound with insulated wire, one end of
which is connected to one, two, or more cells of the secondary battery 23, through
the axis of rocking lever 24, the short arm of which is fitted with a soft iron
armature 25, moving in the magnetic field set up by the pole 5 of electro-motor
magnet the longer arm being adapted to close the circuit through the contact
pin 26 adjustably mounted in the insulated cock 27.
a
The other end of the wire is connected through the terminal 10" to opposite
pole of the battery 23.
In order that the vibration of the building or moving vehicle in or upon which
this instrument is placed, may not interfere with the indications when it is
out of action, we attach to the armature spindle 13, or an equivalent suitable
moving part, a catch or stop; this we prefer should take the form of a collar 27º,
in which is cut a nick or slot 28. We attach to the arm a spiral spring, or its
a cock 271,
equivalent, 29, adjusted by pin 30 passing through
and fitted with an adjusting nut 30. When the instrument is out of action, the
arm sinks into the slot 28, and prevents the spindle from turning round.
a

page_text: At any convenient point upon the spindle is cut or mounted a worm 31, which
actuates the wheel train 32, and pointer 33, moving in front of the dial or dials 34,
upon which may be painted, fettered, engraved or otherwise made clear such
words as *Full," Empty, the number of Lamp Hours, or other equivalent
terms, figures or devices easily apprehended by an unskilled attendant.
The operation of our invention will be readily understood by means of the dia-
gram of circuits shewn in Fig. 6. In charging the secondary battery, the main
current will flow in the direction of the arrows from the brush of dynamo
machine D through the battery 23, and motor electro-magnet a shunt being taken
from one or more cells of battery 23, through brush 16, armature 12, rocking
lever 24, coils of regulating electro-magnet 11, to negative pole of dynamo D.
The magnetisation of the pole piece of the motor attracts the armature 25
fitted to the arm of rocking fever 24, thereby lifting the longer arm out of the
slot 28, on collar 27", fitted to the spindle 13, and closing the brake circuit through
the contact pin 26 and brake electro-magnet coils.
The spindle of motor 13 being released as described the armature of motor will
run in a direction due to a charging current, the brake armature 22 being by
the direction of rotation and the interaction of slot 18 and pin 19 brought as close
as required to the poles of brake magnet, so as to produce the required control.
The revolutions of the spindle 13 are transmitted by the worm 31 or by equivalent
means to the clock work train 32, and the total revolutions recorded by the pointer
-as hours of charge or as "Fuli," etc. Upon discharging, (the driving power
being cut off from the dynamo machine) the current will flow from the pole of
battery 23 to the lamp circuit, and thence in the reverse direction round the
coils of the electro-motor to its pole; the direction of rotation of the armature,
worm and clock train being reversed; the pointer will travel in the reverse
direction, thus shewing the gradual decrease of charge, or the amount of charge
remaining in the cells. As a consequence of the reversal of motion the brake
armature 22 will be removed to a greater distance from the poles 5 of the brake
electro-magnet, and its retarding action upon the motor being diminished the
loss of energy as between charge and discharge is correctly accounted for.
An important feature of our invention consists in the fact that for the purpose
indicated it is not necessary that the coils of the motor should be so arranged as
to necessitate the saturation of the field magnet poles, or the circulation of a
constant current through them. Our apparatus is quite effective when placed
in a railway van to indicate the state of charge in a secondary battery charged by
the varying speed, and consequently varying current, of a dynamo machine
driven from the axle as in train lighting. The braking action we employ is
brought about by magnetic drag, and not by the retarding influence of (Foncault)
or eddy currents.
We'd not confine ourselves to the exact arrangement or coupling up the
operative parts shewn, for instance the brushes conveying current to the armature
may be coupled in series or in parallel with the coil or coils of the brake magnet,
or this magnet may be operated from an independent battery or other source of
electrical energy.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we declare that what we
claim is
(1.) In a charge indicator for secondary batteries. The particular combination
and arrangement of interacting parts connected and operating in the manner shewn
for the purposes set forth.
(2.) In apparatus for shewing the state of charge in a secondary battery. The
combination and use of a fixed electro-magnet and a revolving iron ring or
equivalent brake armature mounted upon a sleeve. the position of said rin or
disc with regard to the magnet pole varying with the direction of rotation of the

page_text: motor but so that the magnetic drag shall be greatest during the charging opera
tion.
"
(3.) In a brake for controlling a charge indicator. The combination and use
of a revolving iron ring or equivalent armature mounted upon a sleeve, the
helical slot in said sleeve and the pin in motor spindle engaging therewith so
that the ring or equivalent armature is advanced by the direction of rotation
towards the magnet poles during charge, and withdrawn during discharge.
Dated this 17th day of December 1898.
FRANCIS M. ROGERS,
Agent for Applicant, 21, Finsbury Pavement.