An Electrical Watt Meter.
Year: 1889

page_text: Date of Application, 6th Nov., 1889
Complete Specification Left, 31st July, 1890-Accepted, 13th Sept., 1890
PROVISIONAL SPECIFICATION.
An Electrical Watt Meter.
I, ERNEST WILSON, of No. 2 Rosemount, Church Lane, Charlton, in the County
of Kent, Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to an electrical instrument which measures and registers the
number of watts consumed, that is to say, a number which is proportional to the vary-
ing electro-motive force or volts, and to the varying current or ampères in a given
time. For this purpose, I apply an automatic break solenoid, excited by the current
or a known fraction thereof, to give reciprocation to an anchor acting on an escape-
ment wheel to cause a spindle, which I may term the main spindle of the instrument,
to revolve at a speed which is proportional to the electromotive force or volts of the
exciting current. The main spindle drives a disc or cone, and also by means of a
bevil wheel drives two opposite bevil pinions which are free on a transverse spindle,
but either of which can be clutched to the transverse spindle by a clutch sleeve sliding
between them. This clutch sleeve is connected to an armature between two electro-
magnets, or to the core of a solenoid subject to the strain of a spring, so that
according as the one or the other of the two electromagnets is excited or according as
the solenoid is excited or not, the clutch is moved so as to engage the one or the other
of the two bevil pinions to the transverse spindle, causing that spindle to rotate in the
one direction or the other.
As the work which the transverse spindle has to do is very little, a friction cone
clutch may be employed, or the pinions themselves may be frictionally driven, the one
or the other being driven when it is pressed against the conical bevil wheel.
The coils of the two electro magnets are connected by conductors to two contacts
on opposite sides of the arm of an ammeter or electro-dynamometer, the axis of which
is geared to the transverse spindle.
When the arm of the ammeter or electro-dynamometer is in middle position, neither
of the electromagnets is excited or both are equally excited and consequently the
transverse spindle remains at rest.
But when the ammeter or dynamometer is excited by an increase or decrease of the
current in its coils (which may be the whole current or a known fraction thereof) its
arm is deflected to the one side or the other and makes one of the contacts or breaks
the other so that the one or the other of the two electromagnets moves the clutch or
the hevil pinions, and the transverse spindle is caused to rotate in such direction as
brings back the arm to its middle position.
The action is similar when a solenoid is employed, instead of the two electro-
magnets, the contact for its coil being made or broken according as the arın is
deflected to the one side or the other. For alternating currents, the solenoid is
necessarily employed. The transverse spindle, when it is caused to rotate as above
described, moves a roller which is pressed by a spring against the face of the disc or
of the cone driven, as before stated, by the main spindle, causing this roller to
approach or to recede from the centre of the disc or to approach or to recede from
the apex of the cone, and thus causing it to revolve by frictional contact at greater or
less speed according as it is farther from or nearer to the axis. The roller spindle is
geared to a counter having dials and indices which register numbers proportional to
the varying velocity of the roller and the time during which it revolves, these numbers
therefore represent the watts passed through the instrument. When an electro-
dynamometer is employed instead of an ammeter, the deflection is proportional to the
square of the current. In order to accommodate the instrument to record numbers
proportional to the current simply, I may employ a conoid of suitably curved outline

page_text: instead of the cone for driving the counting roller, or I may connect the slide of the
roller spindle to the transverse spindle by a volute pulley or gear of such shape as to
compensate by a greater or less movement of the roller for the effect of the dynamo-
. meter in acting according to the square of the current.
Instead of driving the main spindle by an automatic break solenoid acting on an
anchor and escapement wheel, as above described, it might be driven by an electric
motor working at speed proportional to the electro-motive force of the current.
In cases where the electromotive force is constant or nearly so, as in many instal-
lations, the main spindle might be driven by clock work or other motor at constant
speed.
Dated this 6th do of Na
1000
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Electrical Watt Meter.
I, ERNEST WILSON, of No. 2 Rosemount, Church Lane, Charlton, in the County
of Kent, Electrical Engineer, 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 electrical instrument which measures and registers the
number of watts consumed, that is to say a number which is proportional to the
varying electromotive force, or volts and to the varying current, or ampères, in a
given time.
a
I will describe the invention with reference to the accompanying drawings in which
Fig. 1 shews a plan and
Fig. 2 an elevation of the instrument.
An automatic break solenoid A excited by the current or a known fraction thereof
is made to give reciprocation to an anchor acting on an escapement wheel so as to
cause a spindle a which I may term the main spindle of the instrument, to revolve at
speed which is proportional to the electromotive force, or volts, of the exciting
current. The main spindle drives a disc C or it might be a cone, and also by means
of a bevil wheel 6 on a counter spindle a driven from a drives two opposite bevil
pinions which are free on a transverse spindle d but either of which can be
clutched to the transverse spindle d by a clutch sleeve e sliding between them. This
clutch sleeve is connected to an armature between two electro magnets E¹ E³, or it
might be to the core of a solenoid subject to the strain of the spring arm g so that
according as the one or the other of the two electro magnets E' E' is excited, or
according as the solenoid is excited or not, the clutch is moved so as to engage the
one or the other of the two bevil pinions c¹ to the transverse spindle d causing that
spindle to rotate in the one direction or the other. As the work which the transverse
spindle d has to do is very little, a friction cone clutch may be employed, or the
pinions c¹ may be without teeth and frictionally driven, the one or the other being
driven when it is pressed against the conical bevil wheel b. The coils of the two
electro magnets E' E' are connected by conductors to two contacts i¹³ on opposite
sides of an arm ; which is fixed to the movable coil or magnet of an electro-dynamo-
meter, or ammeter B, the axis of the torsion head of which is geared to the transverse
spindle d. When the arm of the ammeter, or electro dynamometer is in middle
position neither of the electro magnets E' E is excited, or both are equally excited,
and consequently the transverse spindle d remains at rest. But when the ammeter,
or electro dynamometer is excited by an increase or decrease of the current in its
coils (which may be the whole current or a known fraction thereof) its arm is deflected
'to the one side or the other, and makes one of the contacts, or breaks the other so
that the one or other of the two electro magnets E! E' moves the clutch or the bevil
pinions, and the transverse spindle d is caused to rotate in such direction as brings
back the arm j to its middle position. The action is similar when a solenoid is

page_text: employed instead of the two electro magnets E¹ E³, the contact for its coils being
made or broken according as the arm is deflected to the one side or the other.
"
For alternating currents the solenoid is necessarily employed. The transverse
spindle d when it is caused to rotate as above described, moves a roller r which is
pressed by a spring against the face of the disc (or cone, driven as before stated by
the main spindle a causing this roller r to approach or recede from the centre of the
disc C or to approach or recede from the apex of the cone, and thus causing it to
revolve by frictional contact at greater or less speed according as it is further from or
nearer to the axis. The roller spindle k is geared to a counter D having dials and
indices which register numbers proportional to the varying velocity of the roller and
the time during which it revolves, and which therefore represent the watts passed
through the instrument. When an electro dynamometer is employed instead of an
ammeter, the deflection is proportional to the square of the current. In order to
accommodate the instrument to record numbers proportional to the current simply, I
may employ a conoid of suitably curved outline, instead of the cone, for driving the
counting roller r or I may connect the slide of the roller spindle to the transverse
spindle d by a volute pulley p or gear of such shape as to compensate by a greater or
less movement of the roller for the effect of the electro dynamometer acting accord-
ing to the square of the current.
In cases where a constant current is employed, and a varying E.M.F.,
I may
employ the instrument B as a shunt to the main circuit and of high resistance so as
to make the distance of the friction roller away from the axis of rotation of the disc
or cone proportional to the volts at which the current is supplied.
Instead of driving the main spindle a by an automatic break solenoid A acting on
an anchor and escapement wheel as above described it may be driven by an electric
motor working at speed proportional to the E.M.F. of the current.
In cases where the E.M.F. is constant or nearly so, as in many installations the
main spindle a may be driven by clockwork or other motor at constant speed.
Fig. 3 represents diagrammatically how a Watt meter such as has been described
can be connected up to the mains carrying the electric energy. M represents the
main coils of the electro dynamometer or ammeter, which may or may not form a
shunt to the main circuit. R represents the external circuit. E' E' represent the
electro magnets or an equivalent solenoid which can also be actuated by a separate
battery. are the contacts on each side of the arm as previously described. A is
the break solenoid for which clockwork or other suitable motor could be substituted.
Gis the generator which may be a dynamo, a set of secondary batteries, or other
source of electricity.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An electrical Watt meter wherein a disc or cone caused to rotate at speed pro-
portional to the electromotive force of the current gives motion to the indices of a
counter through a friction roller which is pressed against the disc or cone at a distance
from the axis of rotation proportional to the current as determined by an ammeter or
electro dynamometer, substantially as herein described.
2. In an electrical Watt meter such as is above referred to, in combination with
the ammeter or electro dynamometer B, the contacts and j, the electro-
magnets E' E' and their armature or an equivalent solenoid and core, spring urged
spindle d with its reversing gear cand e and with its pulley p by which spindle
the torsion head of B is restored to middle position and at the same time the counter
roller is moved to or from the axis of the disc or cone, substantially as described.
T
Dated this 31st day of Inl 1890
ABEL & IMRAY,
Agents for the Applicant.