A HYDROMETER ESPECIALLY APPLICABLE FOR INDICATING THE ELECTRIO CONDITION OF SECONDARY OR STORAGE BATTERIES
Year: 1884

page_text: I, THOMAS PARKER, of The Wolverhampton Electric Light, Storage and
Engineering Company, Commercial Road, Wolverhampton, in the County of
Stafford, Electrical Engineer, do hereby declare the nature of my invention for
A HYDROMETER ESPECIALLY APPLICABLE FOR INDICATING THE ELECTRIO CONDITION
OF SECONDARY OR STORAGE BATTERIES, to be as follows:-
My hydrometer which is especially applicable for indicating the electric
condition of secondary or storage batteries is for use in all descriptions of such
batteries in which the density of the liquid in which the electrodes are immersed
changes as a result of the electric action. This hydrometer operates upon the
principle of the hydrostatic balance, and is constructed as follows:-To one end of
a scale beam, and submerged within the battery solution, is suspended, by a
platinum wire or other suitable means, any weight incapable of being acted upon
by the solution employed. To the other end of the scale beam is attached an
adjustable balance weight, and from the centre of the beam a pointer is carried
down to an index face.
The balance is adjusted so that the weight within the liquid rises as the battery
is charged, that is as the solution therein increases in density. As the submerged
weight rises it causes therefor the pointer to indicate the quantity of electricity
charged and the amount accumulated within the battery. As the battery
discharges, and the density of the solution is consequently lessened, the submerged
weight sinks within the solution and the pointer arm therefore indicates a
decreased accumulation of electricity within the battery, and consequently also the
quantity of electricity discharged. As the submerged weight rises, the pointer arm
acts as a counter-balance in the same manner as the pointer of an ordinary
chemical balance.
The submerged weight may be formed conveniently of a glass tube or globe
loaded with mercury, shot, or other material convenient for adjustment to the exact
weight; the mouth or opening of the tube or globe being of course sealed up after
the insertion of the loading material.
The above described apparatus, acting through a considerable depth of the liquid,
and being capable of very sensitive adjustment, makes an extremely convenient
and reliable instrument for the purpose described.

page_text: The pointer arm, scale beam, or any convenient part of the apparatus, is
employed to form an electric contact to signal either the complete charging or
complete discharging of the accumulator, or any desired condition of the battery.
The apparatus above-described may be used with any cell of a set forming a
secondary or storage battery.
An apparatus mado substantially as above described may be employed as a
hydrometer for the purpose of testing the specific gravity of liquids generally and
for indicating any variation in such gravity.

page_text: I, THOMAS PARKER, of Elwell-Parker Limited (formerly the Wolverhampton
Electric Light, Storage and Engineering Company) Commercial Road, Wolver
hampton in the County of Stafford, electrical engineer, do hereby declare the
nature of my invention for A HYDROMETER ESPECIALLY APPLICABLE FOR INDICATING
THE ELECTRIC CONDITION OF SECONDARY OR STORAGE BATTERIES and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accompanying
drawings and the letters of reference marked thereon:
My hydrometer, which is specially applicable for indicating the electric condition
of secondary or storage batteries, is for use in all descriptions of such batteries in
which the density of the liquid in which the electrodes are immersed changes as a
result of the electric action.
This hydrometer operates upon the principle of the hydrostatic balance, and is
constructed in the manner shewn by the drawings, of which figure 1 is a side
elevation and figure 2 an end elevation. A is a pillar or standard fixed upon a
board or base-plate B. C is a quadrant. D is a cross-bar or gudgeon forming the
axis of the quadrant, and E a screwed lever projecting from the boss of the.
quadrant on the opposite side of the centre to that on which the quadrant projects.
F is a balance weight screwed upon the lever E so as to be adjustable thereon,
and G is a pointer of ivory or other suitable inaterial fixed in the end of the screwed
lever E. The quadrant C and lever E together form a scale beam, and these parts,
with the balance weight F and pointer G, are carried by means of the silken
thread a a a suspended from an arm H projecting from the top of the pillar A.
The silken thread a aa passes across the top of the arm H, down through two
holes therein, and thence through two holes in the cross bar D, below which knots
are tied to form the connection. This method of suspending the quadrant and
lever etc. forms a very delicate and sensitive point about which the balance can
turn, but the gudgeon may be carried upon knife-edges similarly as in the case of
an ordinary scale beam, if desired. b is a silken thread fixed to a groove in the
periphery of the quadrant C so as to lap around such quadrant as the lever E
descends and the quadrant C is raised; and c is a platinum wire which passes from
the thread b down through a hole in the board or plate B into the solution
contained in one of the cells of the battery of which it is desired to ascertain the.
electric condition. J is a glass bulb or tube suspended within the battery solution
at the bottom of the wire c, and forms, when loaded and submerged in the battery
solution, the counter-balance to the weight F. This bulb or tube J is loaded to any
desired extent with shot or other convenient weight or weights as may be necessary
for the purpose for which it is to be employed, and after such loading is of course
sealed up: This bulb J is shewn detached in the drawing, simply for convenience
of illustration. K is an index face marked to shew Ampere hours or other
indications of the charge, as desired. L L are simply blocks forming a cradle in
which to carry the bulb B when the apparatus is packed for carriage.
The hydrometer is preferably covered with a glass case to prevent, as far as
possible, access of dust or moisture to the parts.
The weight within the liquid of course rises us the battery is charged, that is as
the solution therein increases in density. As the submerged tube rises it causes,

page_text: therefore, the pointer to indicate the quantity of electricity charged and,
consequently, the amount accumulated within the battery. As the battery dis
, charges and the density of the solution is consequently lessened, the submerged
tube sinks within the solution and the pointer therefore indicates a decreased
accumulation of electricity within the battery and, consequently, also the quantity
of electricity discharged.
The above-described apparatus, acting through a considerable depth of liquid and
being capable of very sensitive adjustment, makes an extremely convenient and
reliable instrument for the purpose described, and may be used with any cell of a
set forming a secondary or storage battery.
The pointer arm, quadrant, or any convenient part of the apparatus, may be
employed to form an electric contact to signal either the complete charging or
complete discharging of the battery, or any desired condition of the battery; for
instance, a transverse platinum wire d, figure 3, may be carried by the pointer
arm G¹ (shewn in transverse section, figure 3), and such wire connect the opposite
poles e e, from a battery or other source of electricity, so as to form an electric
circuit, and such an arrangement may be adopted at either the highest or lowest
points of the movement of the pointer, or at both of such points, as will be readily
understood. The circuit may be utilized for cutting the battery out of its own
charging circuit or putting it in such charging circuit, as will be readily
understood.
An apparatus made substantially as above described may be employed as a
hydrometer for the purpose of testing the specific gravity of liquids generally, and
for indicating any variation in such gravity, and for signalling the attainment of
any degree of gravity.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be perforined, I declare that what
I claim is
1. A hydrometer for testing the specific gravity of liquids generally, and for
indicating any. variation in such gravity, and specially applicable for indicating
the electric condition of secondary or storage batteries, such hydrometer acting ou
the principle of the hydrostatic balance, substantially as herein described and
shewn by the drawings.
2. In a hydrometer employed for the purposes above described, the combination
of a quadrant, weighted lever, weight suspended from the quadrant, and pointer
and index, all constructed and operating substantially as herein described and
shewn by the drawings.
3. In a hydrometer employed for the purposes above-described, suspending the
quadrant and weighted lever (or equivalent part such as a scale beam), by means
of a silken or other thread or cord, substantially as herein described and shewn by
the drawings.
4. In a hydrometer employed for the purposes above-described, the glass tube J,
substantially as and for the purpose set forth.
5. In a bydrometer employed for the purposes above-described, means for
signalling the condition of a battery or the gravity of a liquid, and also the use of
such or similar means for the purpose of putting a battery into and out of circuit
with a charging current, substantially as set forth.
Dated this sovanth
£ 100%
STEPHEN WATKINS,
Wolverhampton,
Agent for the Applicant.