IMPROVEMENTS IN ELECTRIC METERS
Year: 1883

page_text: LETTERS PATENT to Gilbert Hammersley of Essex Road in the county of
Middlesex and Charles Henry Worsey of Forest Gate in the county of Essex
PROVISIONAL SPECIFICATION left by the said Gilbert Hammersley and
Charles Henry Worsey at the Office of the Commissioners of Patents on the
19th July 1883.
"
GILBERT HAMMERSLEY of Essex Road in the county of Middlesex and CHARLES
HENRY WORSEY of Forest Gate in the county of Essex IMPROVEMENTS IN
ELECTRIC METERS
"
Our invention relates to apparatus for measuring and registering the electrical
power passing through a circuit. For this purpose, according to one arrangement,
we provide clockwork, which may be worked by the electricity passing through the
circuit or part thereof, and which is timed by a balance or pendulum to an approxi-
mately uniform speed. To this clockwork is connected a pair of levers for working
the reciprocating pawl of a counter, this pawl preferably acting, not on teeth, but
as a silent feed. There is a pin, moveable along slots in the two levers, so as to
approach the fulcrum of the one as it recedes from the fulcrum of the other. The
pin is moved by the core of a controlling solenoid excited by the current or a
known fraction thereof, the position of the pin in the slots of the two levers being
thus made dependent on the amount of current. The one lever being caused to
reciprocate by the clockwork, causes the other lever to give to the counter, at each
stroke, an amount of feed proportional to the current, and therefore the counter, in
a given time, registers a total proportional to the current that has passed in that
time. To provide for variations of electromotive force, we may wind the controlling
solenoid with two coils, one of low resistance to be affected by variations of current,
and one of high resistance to be affected by variations of electromotive force, so
that the feed of the counter may be determined by both conditions. According to
another arrangement, we provide a governing solenoid, wound with a coil of high
DC71

page_text: resistance, and arrange its core to move a regulator which varies the length of the
pendulum or balance spring by which the clockwork is timed, so that the speed of
the clockwork increases with the electromotive force. Instead of employing a
pendulum or balance for governing the speed of the instrument, we may, when
great accuracy is not required, use a dashpot or flyer,; and apply the governing
solenoid to vary the discharge or level of air or liquid employed as resistance. The
counter may be made to give its indications by indices on graduated dials, or by
marking a travelling strip of paper, or by both. When clockwork moved by
weight or spring is employed as the motor, we provide a detent, which is with-
drawn by the current, so that there is no movement except' when a current is
passing through the circuit.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Gilbert Hammersley and Charles Henry Worsey in the Patent
Office on the 9th January 1884.
GILBERT HAMMERSLEY of Essex Road, in the county of Middlesex, and CHARLES
HENRY WORSEY of Forest Gate, in the county of Essex "IMPROVEMENTS IN
ELECTRIC METERS "
Our invention relates to apparatus for measuring and registering the electrical
power passing through a circuit. For this purpose, according to one arrangement,
we provide clockwork which may be worked by the electricity passing through the
circuit, or part thereof, and which is timed by a balance or pendulum to an approxi-
mately uniform speed. To this clockwork is connected a pair of levers for working.
the reciprocating pawl of a counter, this pawl preferably acting, not on teeth, but
as a silent feed. There is a pin, moveable along slots in the two levers, so as to
approach the fulcrum of the one as it recedes from the fulerum of the other. The
pin is moved by the core of a controlling solenoid, excited by the current or a
known fraction thereof, the position of the pin in the slots of the two levers being
thus made dependent on the amount of current. The one lever being caused to
reciprocate by the clockwork, causes the other lever to give to the counter, at each
stroke; an amount of feed proportional to the current, and therefore, the counter, in
a given time; registers a total proportional to the current that has passed in that
time. To provide for variations of electromotive force, we may wind the controlling.
solenoid with two coils, one of low resistance to be affected by variations of current,
and one of high resistance to be affected by variations of electromotive force; so
that the feed of the counter may be determined by both conditions. According to
another arrangement, we provide a governing solenoid, wound with a coil of high
resistance, and arrange its core to move a regulator which varies the length of the
pendulum or balance spring by which the clockwork is timed, so that the speed of
the clockwork increases with the electromotive force. Instead of employing a
pendulum or balance for governing the speed of the instrument, we may, when
great accuracy is not required, use a dash pot or flyer, and apply the governing
solenoid to vary the discharge or level of air or liquid employed as resistance. The
counter may be made to give its indications by indices on graduated dials, or by
marking a travelling strip of paper, or by both. When clockwork moved by
weight or spring is employed as the motor, we provide a detent, which is with-
drawn by the current so that there is no movement except when a current is
passing through the circuit.
Fig. 1 of the accompanying drawings is an elevation, partly in section, and fig 2
is a plan of an electric meter according to our invention. A and B are two separate
solenoid coils in one axial line, and C is a core which is strained to its middle
position by springs. The rod of this core works a lever D, and, at the same time,
works a. lever E, which, as the the core approaches either end of its stroke, acts on a
contact lever F, so as to cut out of circuit one of the coils A B, and bring the other
of these coils into circuit. Thus the core C is caused to reciprocate up and down.
while the instrument is in circuit, moving the lever D. In order to regulate the
movements, the core C might be provided with a dash pot, or its reciprocation
might work a flyer or other regulator, but we prefer to employ it to work an
escapement regulated by a pendulum or balance. For this purpose on the head G
of the rod of the core C, we mount two spring pawls, which act on two ratchet
wheels Hand H¹, the one being moved by the upstroke and the other by the.
downstroke. On the axes of these ratchet wheels are bevil wheel h¹, both gearing

page_text: with a bevil pinion, by which motion, always in one direction, is communicated to
a clock or watch movement K. The lever D is slotted, as shewn, and another
lever L, also slotted, is mounted at the side of D, a pin l, capable of sliding in the
slots connecting the two levers. This pin is linked to one arm of a bent lever M,
the other arm of which is linked to the core N of a solenoid P. The current to be
measured, passing, through the coil of this solenoid, causes the core N to be drawn
in, in opposition to spring Q, the farther, the greater the current, and the pin
being thus moved along. the slots in the two levers D and L causes the latter to
make a less or greater stroke, according as a less or greater current excites the
solenoid P. The lever L is provided with pawls, acting on two ratchet: wheels, R
and R¹, which, by means of bevil gearing, give continuous motion to a counter S.
The indices of this counter will therefore move the farther, the greater the current.
When the core N arrives at the upper extreme of its stroke, it raises a contact
spring T, and thus throws the solenoids A and B out of circuit, thereby causing
the movement to stop until the current, again acting in P, draws down N and thus
allows the spring T to make contact again. Obviously, the lever D might be
moved by clockwork driven by a weight or spring instead of the electrical move-
ment described. The core N, instead of being of soft iron, may be a permanent
magnet, so as to render its movement into the solenoid more: nearly proportional
to the current. Also, the solenoid P may be wound with two coils, one of low
resistance, through which the main current passes, and one of high resistance in a
by-pass circuit to the main circuit. Or it may have a single coil of low resistance,
the core N being a coil of high resistance.
Having thus described the nature of our invention, and in what manner the same
is to be performed, We claim:-
In an electric meter, the use of a pair of levers connected by a sliding pin moved
from the fulcrum of the one towards the fulcrum of the other by a solenoid. core,
subject to the action of the current to be measured, one of the levers being thus
made to receive from the other a greater or less stroke according as the current is
greater or less, substantially as herein described.
one
thousand eight
In Witness whereof, I the said Gilbert Hammersley have hereunto set my hand
and seal this ninth day of January in the year of our Lord,
hundred and eighty-four.
GILBERT HAMMERSLEY. (L.S.)