IMPROVEMENTS IN ELECTRIC METERS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Charles Vernon Boys at the
Office of the Commissioners of Patents on the 2nd February 1882.
CHARLES VERNON BOYS of Wing near Oakham in the County of Rutland.
"IMPROVEMENTS IN ELECTRIC METERS."
In a Provisional Specification lodged by me in the Great Seal Patent Office on
the 13th October 1881 No. 4472 I described an electric-meter for measuring the
electricity passing through a conductor by applying an electro-magnet or solenoid
having its coil in the circuit to govern by its attraction an oscillating balance, and
indicating by a counter the number of the oscillations so governed, the number so
indicated being a measure of the electricity. My present Invention relates to
another construction an arrangement of electric meter which is of the following
kind. I keep a balance oscillating by clockwork and employ as the spring of this
balance a long strip of elastic metal by which the balance is suspended, the torsion
of this strip acting as the balance spring. This spring passes through a long slit
in the arm of a lever which has another arm at right angles to the former connected
to the armature of an electro-magnet or to the core of a solenoid having its coil in
the circuit. The armature or core is drawn in one direction by the attraction of
the magnet or solenoid coil and drawn in the opposite direction by an adjustable
spring in such a manner that the slotted arm of the lever takes a position embracing
the torsion spring, determined by the current passing through the coil, leaving only
that part of the spring between it and the balance free to twist and untwist, the
free part being shorter the greater the current passing through the coil. The
velocity of oscillation of the balance is thus so proportioned to the current that an
index moved by the clockwork which is governed by the balance registers the
amount of current passing through the coil in a given time. Instead of passing
the whole current through the coil, a known fraction of it may be passed, and one
two or more such fractions may be brought into circuit or excluded from circuit
uccessively by a subsidiary magnet as the lever approaches convenient limits of
Paine 621

page_text: its range, corresponding indices of the counter being simultaneously brought into
or thrown out of action, the range of the apparatus being thus extended so as to be
applicable for measuring large variations of current. In this case the gearing for
working the indices of the counter may be provided with magnetic clutches which
are made to clamp or unclamp them successively as the several different circuits are
established.
In the Specification to Letters Patent granted to me on the 3rd June 1881
No. 2449 I described a method of integrating a varying electric force by pressing
against the surface of a longitudinally reciprocating cylinder the edge of a disc
having its plane more or less inclined to the axis of the cylinder, the cylinder being
thus caused to turn more or less round its axis as it moves longitudinally in frictional
contact with the inclined disc.
I combine this integrating apparatus with the electric meter above described by
making the axis of the lever of the latter also the axis on which the disc swivels
so that the plane of the disc is always made to coincide with the arm of the lever
that is moved by the armature or solenoid core. The number of revolutions or
parts of a revolution of the cylinder can be indicated by a counter as described in
the Specification above referred to, and the cylinder being caused to reciprocate by
the clockwork governed by the torsion balance the amount of its revolution will
measure the integral of the electric force.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Vernon Boys in the Great Seal Patent Office on the
1st August 1882.
CHARLES VERNON BOYS of Wing near Oakham in the County of Rutland.
"IMPROVEMENTS IN ELECTRIC METERS."
In the Specification to Letters Patent granted to me on the 13th October 1881
No. 4472 I described an electric meter for measuring the electricity passed through
a conductor by applying an electro magnet or solenoid to govern by its attraction
an oscillating balance so that the number of oscillations of such balance as
indicated by a counter gives a measure of the electricity passed through the coil of
the electro magnet or solenoid. My present Invention relates to another construc-
tion and arrangement of electric meter which I will describe referring to the
accompanying Drawings. Fig. 1 is a side view, Fig. 2 a back view and Fig. 3 a
plan. A balance wheel A is suspended by a long flat spring B which passes
through a slit in a lever arm C pivotted at c and counterbalanced by a weight C¹
and drawn upwards by an adjustable spring C. On this arm near its pivot is
fixed a cylindrical armature D near the poles of an electro magnet E whose coils
are in the main circuit. According as a greater or less electrical current passes
through the coils of E, the armature D is more or less attracted, the arm C being
thus more or less depressed shortening to a greater or less extent the length of
spring B below the slit of C in which it is engaged and thus more or less
accelerating the oscillations of the balance A. Thus the number of oscillations of
A in a given time as indicated by a counter worked from the axis of A will
measure the quantity of electricity that has in that time passed through the coils
of the electro-magnet E. The oscillations of the balance A might be maintained
by clockwork or by remontoir apparatus giving the balance either uniformly
recurring or occasional impulses as described in the Specification of No. 4472 of
1881 above referred to. In the accompanying Drawings I have shewn means of
giving occasional impulses as I will now describe. Across the balanco A I fix an
iron bar which forms the armaturo of an electro magnet P. The coils of this
electro magnet are occasionally brought into connection with the main circuit by
the action of the grooved stud on the hanging finger n causing contact of the
springs N N as described with reference to Fig. 10 of the Drawings accompanying
the said Specification No. 4472 of 1881, this connection being effected only when
the excursion of the stud is so much reduced that the finger n is caught and held
in its groove. The magnet P being in that case excited attracts the armature Q
thereby giving an impulse to the balance A.
In order to ensure the starting of the balance when it is put in electrical circuit,
I make provision for its always stopping when cut out of circuit in such a position
that there is torsion of the spring B ready to start it when it is again put in circuit.
For this purpose I employ a detent lever F having at its upper end an armature G.
When no electricity passes through the coils of E the lower end of the lever F
advancing towards the edge of the balance wheel becomes engaged with a ratchet
stud H projecting therefrom and holds the balance in such a position that there is
torsion of the spring B. When the apparatus is put in circuit the armature G is
attracted and the lower end of the lever, F is thus withdrawn from the face of the
stud H, whereupon the balance starts into oscillation. The number of oscillations
are recorded by any convenient counter which may be worked by a spring pawl
attached to the bar Q acting on a ratchet wheel R geared to the counter.
Instead of passing the whole current through the coils of E a known fraction of

page_text: it may be passed, in which case the number of oscillations recorded by the counter
will be proportionally reduced.
In the Specification to Letters Patent granted to me on the 3rd June 1881,
No. 2449 I described a method of integrating a varying electric force by pressing
against the surface of a longitudinally reciprocating cylinder the edge of a disc
having its plane more or less inclined to the axis of the cylinder, the cylinder being
thus caused to turn more or less round its axis as it moves longitudinally in
frictional contact with the inclined disc. Such integrating apparatus might be
combined with the electric meter above described by making the axis of the
lever C also the axis on which swivels a disc that is pressed against a cylinder
caused to reciprocate longitudinally as described in the said Specification No. 2449
of 1881.
Having thus described the nature of my Invention and in what manner the same
is to be performed, I claim :-
First. The herein described method of measuring and registering the electricity
passed through a conductor by counting the oscillations of a balance wheel governed
by a torsion spring, the torsive length of which is determined by a lever acted on
by the attraction of an electro magnet having its coil in the circuit of the
conductor.
Second. The construction of electric meter substantially as herein described
with reference to the accompanying Drawings.
In witness whereof I the said Charles Vernon Boys have hereunto set my
band and seal this Twenty-eighth day of July in the year of our Lord One
thousand eight hundred and eighty two.
C. V. BOYS. (L.S.) 2