Improvements in Apparatus for Measuring Electric Currents.
Year: 1885

page_text: Improvements in Apparatus for Measuring Electric Currents.
I ALFRED GEORGE BROOKES of the firm of Wm Brookes & Son of 55 & 56
Chancery Lane in the County of Middlesex Fellow of the Institute of Patent
Agents do hereby declare the nature of my invention for IMPROVEMENTS IN
APPARATUS FOR MEASURING ELECTRIC CURRENTS to be as follows:-
This invention relates to improvements in apparatus for measuring electric
currents; and the object of these improvements to provide such measuring
apparatus with a device or devices for registering the quantity or tension or
quantity and tension of electric energy passing such apparatus.
The apparatus serves principally to control the quantity or tension of electric
energy produced by a central source of electricity as well as the quantity or
tension of electric energy used by each one of the establishments supplied with
electricity from the central source.
An electro-magnet is inserted within a branch, containing the sufficient resist-
ance of the current to be measured and registered in such a manner that the
current passing the conducting wires is closed only when a moveable lever pro-
vided with the adjusting weight rests upon the armature. As soon as the circuit
is closed the anchor of the electro-magnet is drawn towards the latter and thereby
comes in contact at its extremity with the lever in such a manner as to raise it.
Thus the contact between the lever and the armature is completed and the circuit
interrupted. The electro-magnet, which thereby becomes currentless, releases its
armature and the lever returns into its former position, whereafter the like action
begins again.
Instead of introducing the current into the lever a contact device may be
arranged in a suitable manner in order to avoid the passage of the current through
parts of the apparatus itself.
This alternate raising and lowering of the lever causes the intermittent rotation
of a friction or ratchet wheel into which engages a friction clutch and a ratchet
fixed to the moveable lever. To the shaft of the wheel is fixed a drum or reel,
which consequently rotates with the wheel. A paper band of the size of the drum
is drawn nearly around the whole circumference of the drum. Thereby sufficient
friction is obtained for advancing the band by the rotation of the drum.

page_text: In the main circuit are inserted two electro-magnets, between them is placed a
vertical disc or roller composed of a number of iron plates or strips. The disc or
roller is maintained during its normal position by a suitable device, as for instance
by springs, in such a manner as to place its plates or strips at right angles to the
axes of the two electro-magnets. The current introduced into the electro-magnets
magnetizes them, and the magnetic attraction causes the disc or roller to turn in
such a manner as to place the plates or strips of the disc or roller in the direction
of the axes of the electro-magnets. Thus the degree of the rotation of the disc or
roller depends upon the intensity of the current passing through the electro-
magnets. A toothed wheel fixed to the shaft of the disc or roller transmits the
Oscillation of the latter to a rack, which carries a pointer or indicator; thereby any
deviation from the normal position of the disc or roller is marked on the band
advancing with the drum.
A second registering device may be used besides the one just described by
connecting the shaft of the drum with a wheel work, whereby a disc similar to the
dial of a clock is rotated. This disc can be placed either horizontally or vertically
or in any inclined position.
Before, above, or in other proper relative position to such disc slides a pointer or
indicator, which either may be moved by the above described disc or roller
composed of plates or by the core of a solenoid, through which the main circuit or
the circuit to be measured passes or in any other suitable manner.
The disc is rotated by the wheel-work only when the current passes the
conducting wires, and this rotation is regulated in such a manner that the disc
performs one rotation in a certain stipulated unit of time. As corresponding with
the quantity of electric energy passing the main circuit the pointer or indicator
reciprocates before the disc, the curve marked by the indicator upon the disc shows
the quantity or tension of electric energy used during the working-time; the disc
may be provided with concentrical circles, which are arranged in intervals corre-
sponding with the throw of the indicator, in order to facilitate reading off of the
measurements made. The units of time for instance in hours are indicated upon
the disc by radial lines. It is evident that the disc and the mechanism for driving
the same may be employed alone-without the band advanced by the reel-for
registering the quantity or tension of electric energy, which passed the apparatus.
Dated this 92nd dow of T..1... 100K
5.

page_text: Improvements in Apparatus for Measuring Electric Currents.
I ALFRED GEORGE BROOKES of the firm of W Brookes & Son of 55 & 56
Chancery Lane in the County of Middlesex Fellow of the Institute of Patent
Agents, do hereby declare the nature of my invention for IMPROVEMENTS IN
APPARATUS FOR MEASURING ELECTRIC CURRENTS, 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 improvements in apparatus for measuring electric
currents; and consists in the detailed construction and combination of the parts
hereinafter fully described and claimed, by which the quantity or tension or both
the quantity and tension of any circuit of electricity passing through the measuring
apparatus is automatically registered.
In the drawings, Figure 1, is a front elevation of the measuring apparatus.
Figure 2, is a plan view of the same.
Figure 3, is a side elevation of the apparatus, partly in section.
Figure 4, is a front elevation of the mechanism for setting the apparatus in.
motion, also partly in section.
Similar letters of reference indicate corresponding parts in all the figures.
This apparatus is intended to be used principally to indicate the quantity or
tension of electric energy produced by a central source, but it also may be employed
to indicate separately the quantity or tension of electricity supplied to different
establishments from the central source.
It will readily be understood, that in order to make use of this apparatus for
measuring either the quantity or tension of electric energy, electro magnets of
different constructions are required viz. in the first case coils consisting of thick
wire with little electric resistance, and in the other case coils of thin wire and
greater electrical resistance, should be employed.
An electro-magnet a is inserted within any branch of the circuit (containing
sufficient resistance) to be measured and registered; the conducting wires b of this
branch are attached to the said electro-magnet in such manner that the circuit is
closed only when the lever d rests upon the extremity i of the anchor g, as shown
in Figure 4 of the drawings.
As soon as the circuit is closed the armature g. pivoted at his drawn to the
electro-magnet a and thereby the arm i strikes against the spring k of the lever d
in such a manner as to cause a sudden raising of the lever d with its weight c.
By this action the lever d will be thrown considerably higher than the extremity
of the arm of the lever armature g the oscillation of which is limited by the
electro-magnet a; thus the armi and the spring will be separated and the
electric current interrupted. The electro-magnet then becomes currentless releases
the anchor g and allows the lever d to resume its former position, the circuit being
again closed the operation of raising the lever is again repeated.
A friction wheel is journaled upon the same shaft upon which the lever dis
pivotted, and this wheel is made to revolve intermittently by means of a friction
clutch m affixed to the side of the said lever, which is also provided with weight c
near its free end.
The friction clutch m is pivotted eccentrically to the lever d so that it engages
automatically with the wheel and moves it in one direction only; n is a friction

page_text: brake which presses upon the wheel and prevents any return motion from
taking place.
A simple form of registering device may be used; this is shown in the drawings
but although it is not intended separately and specifically to be claimed in this
specification its manner of operation is hereinafter described in order the better to
make my invention understood. When this device is used, a drum t is secured
upon the same shaft as the wheel and rotates with it. A friction roller u is
placed beneath the drum t, and a paper band is wound between them and around
the circumference of the drum t so that the said paper band is advanced by the
rotary motion of the said drum.
The electro magnets o are inserted in the main circuit by means of the con-
ductors p; q is a disc or roller pivotted between the said magnets o; this disc is
composed of a number of iron plates or strips and is maintained in its normal
position by means of the springs v or other equivalent devices.
A toothed wheel s is secured upon the same shaft as the disc q and turns with
it; this wheels gears into the rack r which carries the pointer or marker z which
bears upon the band on the drum t and registers the fluctuations of the current.
A second registering device may also be used, this is driven by means of a train
of wheels E to which motion is imparted by means of a pinion secured upon a con-
tinuation of the shaft which carries the friction wheel l. This train of wheels E
sets in motion a disc A which rotates slowly; this disc may be placed horizontally,
vertically, or in any inclined position as found most convenient. The disc A
rotates only when the current passes through the conducting wires and this rotation
is so regulated that the disc performs one rotation in a certain stipulated unit of
time, with a given quantity of electricity passing through the main current. B is
a pointer or marker which slides before the disc A; this pointer may derive its
motion from the disc q or it may be operated by a solenoid C, to the core D of
which it may be attached.
The manner in which the disc A is made to perform one rotation in a predeter-
mined unit of time, is effected by means of a pendulum or balance employed in the
clockwork E, as the motion, imparted to the latter by the descending of the
weighted lever d, is governed in a well known manner by the oscillation of
the adjustable pendulum or balance.
The current to be measured is made to pass through the solenoid C, so that the
core D projects more or less according to the intensity of the said current.
The disc A may be marked with concentric circles and radial lines to facilitate
the reading off of the measurements made upon it.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is :-
In apparatus for measuring and registering electric currents the combination of
a wheel work, driven by an electric current with one two or more devices
registering either the quantity or the tension or both the quantity and tension of
any circuit of electricity in such a manner as to mark upon surfaces moved by the
wheel work the positions and motions of the indicator or indicators, caused by the
influence of the currents to be measured, substantially as described and illustrated
in the accompanying drawings.