Improvements in Instruments for Measuring and Recording Electric Currents.
Year: 1886

page_text: Date of Application, 12th Aug., 1886.
Complete Left, 10th May, 1887.
Complete Accepted, 28th June, 1887.
PROVISIONAL SPECIFICATION.
Improvements in Instruments for Measuring and Recording
Electric Currents.
I WILLIAM GREENHALGH 40 Kirkland Place Beeston Road Hunslet Leeds
Practical Electrician do hereby declare the nature of this invention to be as
follows:-
My invention relates to an improved method of measuring & recording the electric
current or energy passing through electrical circuits.
In an electrolytic cell I place two electrodes, one being stationary, and the other
suspended by any suitable device, preferably a spring, in such a manner that any
alteration in the weight of the said electrode causes the spring to rise or fall, & so
actuates the recording mechanism. The cell is placed in loop or shunt circuit with
the current to be measured, and by the well known process of electrolysis, the metal
is stripped from one electrode and deposited on the other.
When the metal is being deposited on the suspended electrode, it becomes heavier,
and depresses the spring in proportion to the increase in weight of the said electrode.
The process continues until the spring is depressed such a distance that a stop or catch
attached to said spring releases a train of wheels, which actuate a pointer or hand
indicating the movement on the dial of the instrument, and which said train of wheels
also actuates a current reverser or commutator for reversing the direction of the
current passing through the electrolytic cell.
The train of wheels, which is actuated by any suitable device, continues to revolve
until the direction of the current has been reversed in the electrolytic cell, as before
described, when the said train of wheels is restrained by another stop attached to the
spring carrying the suspended electrode. The action is now reversed, the metal
D
077

page_text: being stripped from the suspended electrode, which becoming lighter, allows the
spring from which it is suspended to rise, until the catch before mentioned again
releases the train of wheels, which revolve (the pointer registering another division
on the dial) and reverses the direction of the current passing through the electrolytic
cell as before. The action continues automatically as long as any current is passing.
A pointer in direct connection with the spring supporting the suspended electrode
indicates the slighest change in the weight of the said electrode.
The inventor prefers a spring for supporting the suspended electrode, as being a
simple device, and arranges the train of wheels, so that they will continue to work for
long periods of time without attention.

page_text: I WILLIAM GREENHALGH 40 Kirkland Place Beeston Road Hunslet Leeds
Practical Electrician 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 an improved method of measuring and recording the
electric current or energy passing thro electrical circuits, & is effected by shunting a
very small portion of the current to be measured thro an electrolytic cell, and
registering the rising & falling of one of the electrodes, suspended from a spring or
other suitable device; the direction of the current thro the cell being automatically
reversed at suitable intervals.
In an electrolytic cell, A Fig. 2 preferably sulphate of copper, is suspended the
electrode B, from a spring C, which is supported from the frame of the Instrument.
In connection, & working with the spring C, is an escapement pallet D, controling
the escape wheel H, fixed upon & carried by the pinion F, Fig. 3 & 4; also fixed
upon pinion F, is the commutator E, working between the brushes J-Gearing
into pinion F is a large wheel L, Fig. 5, carried upon the same spindle as the
pointer K, & actuated & driven by the coiled spring in the spring box G.
The action of the instrument is as follows:-
Upon winding the spring the train of wheels is ready to revolve, but is prevented
from so doing, as the pin in the escape wheel H is resting against the pin in the
pallet D.
A small portion of the current to be measured passes thro the instrument, which
forms a shunt circuit between the terminals, & causes the suspended electrode B to
become heavier or lighter according to the direction of the current, & consequently to
rise or fall in the cell.
When the electrode B has risen or fallen a determined distance, the pallet D,
releases the escape wheel H, & allows the commutator E, to revolve one half turn,
which reverses the direction of the current through the cell; at the same time the
pointer advances one division on the dial.

page_text: Another pointer M Figs. 1 & 2 may be added & actuated directly from the
suspension spring C, so as to indicate finer readings on its accompanying scale, than
those indicated by the pointer K.
The exact details as shewn in the drawings may be varied in many ways without
departing from the particular features of my invention.
Having now particularly described & ascertained the nature of my said Invention, &
in what manner the same is to be performed I declare that what I claim is
The combination of a commutator or current reverser & registering device,
actuated by suitable mechanism, with a suspended electrode in an electrolytic cell, for
the purpose of registering automatically the alternate rise & fall of said electrode, &
by that means the quantity of current passing thro the apparatus.