Improvements in Electric Meters.
Year: 1893

page_text: Date of Application, 15th Feb., 1893
Complete Specification Left, 1st Nov., 1893-Accepted, 9th Dec., 1893
Improvements in Electric Meters.
I WILLIAM CLARK, of the Firm of A. M. & Wm. Clark of 53 Chancery Lane
in the County of Middlesex, Fellow of the Chartered Institute of Patent Agents,
do hereby declare the nature of this invention (a_communication to me by the
Firm of Hartmann and Braun, of Bockenheim-Frankfort-on-Main, Germany,
Manufacturers of Electrical Apparatus) to be as follows :-
This invention relates to a meter for continuous and alternate currents wherein
the indications of a Watt-meter are transmitted at certain intervals to counting
mechanism.
The accompanying drawing illustrates diagrammatically the action of the
instrument.
the screw c.
The
M is the Watt-meter through the thick stationary coils of which the current
used in the main circuit flows whilst the thin movable coils are situated in a shunt
to the main circuit. An arm Z is fixed on the movable bobbin of the Watt-meter
in order that the motion of said bobbin may be confined within narrow limits by
screws c and c¹ and the circuit of the electromagnet E interrupted or closed.
direction of current in the Watt-meter is such that the force resulting from the
action of the current tends to press the arm Z of the movable bobbin against
The electric energy to be measured is in this Watt-meter determined
by the extent to which the spring F attached to the arm Z must be expanded, until
the arm just quits the screw c and swings freely between c and c¹. In order that a
registration of the Watt-meter indications or of the extent of the corresponding
spring expansions, may be obtained, the spring F is expanded by means of a
clockwork U or by an electromagnet acting under the control of clockwork once in
every minute to a maximum point and then released. A roller W is at same time
revolved, and the clockwork is provided with a contact which closes the circuit of
the electromagnet E only so long as the spring is being expanded. As long
as the circuit of the electromagnet E is closed and the current flows through it
the first wheel R of the counter mechanism which is carried by the armature of the
electromagnet E is pressed against the roller W with which it remains in contact
so long as the electromagnet is excited.
The path of the current in the several parts of the electric meter is as follows:-
(a) Thick coils. From terminal 1 to 2 through the main circuit L to 7 through
the thick coils to terminal 6.
(b) Thin coils. From terminal 1 to 2, 3, through the thin coils to 4, 5, and
terminal 6.
(c) Electromagnet E.-From terminal 1 to 14 through the contact lever of the
clockwork to 13, 12, through the coils of the electromagnet E to 11, 10, through
the contact c to arm Z, through the body of the movable bobbin to 8, and thence
to terminal 6.
с
The operation of counting is as follows:-By the use of the current at L the
arm Z is pressed with a certain force upon c. The spring F can then be expanded
by the clockwork or the electromagnet and the contact in the clockwork being
closed and arm Z in contact with e the electromagnet E is excited and R is pressed
against roller W which is forced to turn with the pull on the spring F and performs
a to and fro movement proportional to that of the spring. Directly spring F is so
far expanded that its power balances that of the Watt-meter, the arm Z quits the
contact c the electromagnet circuit is thereby interrupted and R quits the roller W.
A rotatory motion is therefore imparted to the wheel R proportional to the current
action of the Watt-meter. The more electrical energy there is used at L the

page_text: longer Z remains upon c, because spring F must be so much more expanded until
equilibrium ensues, and for so much longer the electromagnet E remains excited,
therefore the wheel R, which is the first member of an ordinary counting.train, is
turned to such a greater extent. At every inward motion of the lever arm of the
clockwork U by which the spring is expanded the electromagnet circuit is interrupted
at the contact lever, or if, for the continuous to and fro motion of the spring, a
special electromagnet be employed, as shewn in the drawing, its circuit will be
periodically closed by the contact of the clockwork. The spring F may be so
arranged that it is used torsionally, instead of by direct tension, by making it act
as a spiral spring, directly upon the axis of the movable bobbin of the Watt-meter.
In order to render the indications of the electric meter dependent on the amount
of current used only, the movable bobbin of the Watt-meter can be replaced in the
known way by a permanent magnet arranged movably in the same manner, in
which case the meter will be a Coulomb counter for continuous current. More-
over the permanent magnet may be so attached that the thick coils traversed by
the current exert thereon an attractive or drawing-in action by which means the
axis upon which the movable bobbin is pivoted may be dispensed with, the magnet
being directly hung upon the spring F. In this case the screws c, c', so retain
the magnet thatproportionality is maintained between the current strength and the
corresponding expansion of the spring. The coupling of the counter mechanism
with the spring may also be effected through the electromagnet by pressing the
roller W against the counter mechanism. The counter mechanism may be pressed
directly against the tension band of the spring by the electromagnet for the purpose
of transmitting the notion by friction.
The clockwork may be of the ordinary kind driven by a spring or weight or by
electrical power.
Dated this 15th day of February 1802 ·
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Electric Meters.
I, WILLIAM CLARK of the Firm of A. M. and Win. Clark, of 53, Chancery
Lane, in the County of Middlesex, Fellow of the Chartered Institute of Patent
Agents, do hereby declare the nature of this invention (a communication to me by
the Firm of Hartmann and Braun, of Bockenheim-Frankfort-on-Main, Germany,
Manufacturers of Electrical Apparatus) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to a meter for continuous and alternate currents wherein
the indications of a Watt-meter are transmitted at certain intervals to counting
mechanism.
The accompanying drawings illustrate diagrammatically the action of the
instrument.
M is the Watt-meter through the thick stationary coils of which the current
used in the main circuit flows whilst the thin movable coils are in a shunt to the
main circuit. The motion of the movable bobbin of the Watt-meter is confined
within narrow limits and the circuit of the electromagnet E is closed or broken by
an arm Z fixed to the movable bobbin playing between the screws c c. The
direction of the current in the Watt-meter is such that the resulting inductive
force tends to press the arm Z against the screw c.
The measurement. of electric
energy is in this Watt-meter determined by the extent to which the spring F must
be expanded until the arm just quits the screw c and swings freely between c and c².

page_text: In order that a registration of the Watt-meter indications, or of the extent of the
corresponding spring expansions, may be obtained, the spring F is expanded once
every minute by means of an electromagnet acting under the control of clock-
work U to a maximum point and then relaxed. A roller W is thereby revolved
and the clockwork is provided with a contact which closes the circuit of the electro-
magnet E only so long as the spring is being expanded. As long as the circuit of
the electromagnet E is closed and the current flows through it, the first wheel R.
of the counter-mechanism, which is carried by the armature of the electromagnet E,
is pressed against the roller W with which it remains in contact so long as the
electro-magnet is excited.
Referring to Figure 1, the path of the current in the several parts of the electric
meter is as follows:
-
(a) Thick coils-From terminal 1 to 2 through the main circuit *L to 7 through
the thick coils to terminal 6.
(b) Thin coils From terminal 1 to 2, 3, through the thin coils to 4, 5, aud'
terminal 6.
(c) Electromagnet E-From terminal 1 to 14 through the contact lever of the
clockwork to 13, 12, through the coils of the electromagnet E to 11, 10, through
the contact c to arm Z through the body of the movable bobbin to 8 and thence to.
terminal 6.
The operation of counting is as follows:-By the use of the current at L the
arm Z is pressed with a certain force upon c. The spring F can then be expanded
by the electromagnet or by clockwork and the contact in the clockwork being
closed and arm Z in contact with c the electromagnet E is excited and R is pressed
against roller W which is forced to turn with the pull on the spring F and performs
a to and fro movement proportional to that of the spring. Directly spring F is so
far expanded that it balances the Watt-meter, the arm Z quits the contact c, the
electromagnet circuit is thereby interrupted, and R quits the roller W. A rotatory
motion is thus imparted to the wheel R proportional to the current action of the
Watt-ineter. The more electrical energy there is used at L the longer Z remains
upon c because spring F must be so much more expanded until equilibrium ensues,.
and for so much longer the electromagnet E remains excited, therefore the wheel R,
which is the first member of an ordinary counting train, is turned to such a greater
extent. At every inward motion of the lever arm of the clockwork by which
the spring is expanded, the electromagnet circuit is interrupted, or if for the
continuous to and fro motion of the spring a special electromagnet be employed,
as shewn in Figure 1, its circuit will be periodically closed by the contact of the
clockwork U. The spring F may be so arranged that it is used torsionally, instead
of by direct tension, by making it act as a spiral spring directly upon the axis of
the movable bobbin of the Watt-meter, as shewn in Figure 2, the action of the
other parts remaining the same.
In order to render the indications of the electric meter dependent on the amount
of current used only, the movable bobbin of the Watt-meter can be replaced in the
known way by a permanent magnet arranged movably in the same manner, in
which case the meter will be a Coulomb counter for continuous current. Moreover
the permanent magnet may be so attached that the thick coils traversed by the
current exert thereon an attractive or drawing-in action by which means the axis
upon which the movable bobbin is pivoted may be dispensed with, the magnet
being directly hung upon the spring F. In this case the screws c c so retain the
magnet that proportionality is maintained between the current strength and the
corresponding expansion of the spring. The coupling of the counter mechanism
with the spring may also be effected through the electro-magnet by pressing the
roller W against the counter mechanism. The counter mechanism may be pressed
directly against the tension band of the spring by the electro-magnet for the
purpose of transmitting the motion by friction.
The clockwork may be of the ordinary kind driven by a spring or weight or by
electrical power.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that, what I
claim is :
1. In an electric meter, the combination, with a Watt-meter whose movable
part rests against an abutment, of a spring which is connected to the movable
portion of the Watt-meter and
put in tension at regular intervals by clockwork
so that it tends to draw the said movable portion away from its abutment, and
counting mechanism actuated during the expansion or torsion of the spring, as
specified.
2. An electric meter of the kind specified in Claim 1, wherein the abutment of
the movable part of the Watt-meter is an electrical contact connected with the
electro-magnet by which the counting mechanism is put into operative position so
that on the breaking of the said contact the counting mechanism is put out
of action.
3. An electric meter of the kind specified in Claim 1, wherein the expansion of
the spring is effected by means of an electro-magnet whose circuit is periodically
made and broken, as described.
4. The special construction of meter wherein the expansion of the spring is
effected by an electromagnet whose circuit is periodically made and broken and
wherein the armature of the said electromagnet is connected to the spring through
a cord working a pulley with which the first wheel of the counting train is put in
gear by an electromagnet energized by the current passing at the contact made
by the movable part of the Watt-meter, as specified.
Dated this 1st day of November 1893.
WM. CLARK,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.