Improvements in Electricity Meters.
Year: 1891

page_text: Date of Application, 8th Jan., 1891
Complete Specification Left, 8th Oct., 1891-4ccepted, 14th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Electricity Meters.
I, FRANCIS TEAGUE, of the Acme Electric Works, Ferdinand Street, Chalk
Farm, in the County of London, Manager, do hereby declare the nature of this
invention to be as follows:-
My invention relates to meters used for recording or measuring electricity, or
the electric energy expended in any working circuit with which a meter is
connected.
A meter, constructed according to this invention, consists of a small motor
actuated by current derived from the said working circuit, and adapted (through
the intervention of a train of wheels), to indicate the energy, in any desired units,
by means of index fingers upon suitably marked dials.
The working principle of the motor is the known one of the rotation of currents
by magnets-experimentally shown by Faraday--and this present invention con-
stitutes improvements upon a former invention of mine, for which British Letters
Patent were granted to me, dated 2nd October, 1889, No. 15,489.
In my said former invention, a copper cylindrical armature was vertically
supported between jewelled pivotal bearings, and it was adapted to make circum-
ferential contacts at the top and bottom of the armature with mercury placed in
suitable concentric troughs. Each trough was separately connected to the working
circuit, and currents circulated through the troughs and the armature, and also
round the field or electro magnets employed.
In practice, however, it was found that the extended circumferential area of the
armature produced much frictional resistance in its contact with the mercury in
the upper trough, when the armature revolved therein; and I have therefore
dispensed with the upper trough altogether. In my present invention I use a
central mercury contact, instead of the upper circumferential mercury contact above
mentioned, but I still employ the lower circumferential mercury contact, as at first.
Furthermore, I make the cylindrical armature of aluminium, instead of copper,
and support it vertically between jewelled pivotal bearings, as before, but I bore a
hole through the polar portions of a horse shoe magnet and fit a soft iron cylin-
drical extension therein, secured to the lower limb of the magnet, but extending
upwards, and leaving an annular space in the upper limb within which the armature
may revolve. The upper portion of the magnet extension is bored to provide for
the lower pivotal bearing of the armature, and the central mercury contact trough ;
while the upper pivot is supported by an overhung bearing secured to the upper
limb of the magnet. The armature axle is bored cup shaped at the bottom, to
receive the jewel for the lower pivot, and the space thus formed is made sufficiently
deep to form a small air chamber. 1 find that this air chamber-by the com-
pression of air therein-serves to protect the lower pivotal bearing from actual
contact with the mercury, and consequently both the bearing and the mercury are
kept clean. As the armature axle is of an appreciable size, it follows that the
mercury of the central contact surrounds the said axle, and, together with the
mercury in the outer annular trough, (at the bottom of the armature), exerts a
buoyant effect upon the armature, which may be made to balance the weight
thereof, and thus reduce the friction from that source to a minimum.
The upper portion of the armature axle is provided with a worm for actuating
a train of wheels with index fingers, in the same manner as that described and
shown for my before mentioned invention, but with the difference that all the wheel
work is mounted in a self contained manner within a framing, and this framing is
mounted vertically in such a manner against the polar ends of the magnet that it

page_text: can be readily and bodily removed therefrom. By doing so, and unscrewing the
overhung bearing, the armature can be lifted out clear of its mercury contacts, for
inspection, for removing the mercury, or for any other purpose.
The lower and outer mercury trough is of iron, of an annular form, and screwed
with a fine thread in the bore. This is made to screw upon a correspondingly
screwed section of an insulating tube of vulcanite, or vulcanized fibre, which fits
upon the central portion of the circular magnet extension before mentioned. By
screwing the annular trough up or down upon the insulating tube, the dip of the
armature in the mercury is increased or reduced as may be required. Around the
circumference of this lower trough is a brass ring clip which is secured upon
the trough by screwing together the open ends of the clip. By screwing the clip
tight, good electrical contact is made with the mercury trough, and by releasing
the closing screw, the trough may be adjusted up or down as required, the clip
being then locked in position by the closing screw. The circuit connection is made
through the metal clip. Surrounding the upper portion of the trough, and resting
upon the clip, is a ring of insulating material having an inward overhanging lip,
closely conforming to the armature, which tends to keep the mercury in place,
whenever the meter is tipped out of level.
In my former invention I employed two conducting coils for energizing the
electro magnets, except in the circular form of meter. In the present invention
I use a single coil to excite the horse shoe magnet, which reduces the cost and
weight, the magnet being conveniently made of two flat limbs, connected together
by a turned yoke or stud, the central part of which is the core for the coil. The
ends of the studs are screwed for fastening nuts, which secures the whole firmly
together. A base of insulating material is adapted to receive the lower limb of
the magnet, and to this is secured-in magnetic contact-the circular polar
extension which is mounted vertically and adapted to carry the armature inside the
hole bored for it in the end of the upper limb of the magnet, as previously
described.
This meter is adapted for continuous currents, with the solid iron magnet limbs,
as described; but if required for alternating currents, the magnet is built of
laminated plates in the manner well known. It is adapted for measuring watts (or
energy) with a compound winding upon the coil, or for a current meter, by a series
winding; for, as the electro motive force rises or falls so does the current rise
and fall, and I find that the rotation of the arinature, and therefore of the index
fingers, is exactly proportionate thereto.
Dated this 7th day of January 1891.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electricity Meters.
I, FRANCIS TEAGUE, of the Acme Electric Works, Ferdinand Street, Chalk
Farm, in the County of London, 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 meters used for measuring or recording electricity, or
the electric energy expended in any working circuit with which a meter is
connected.
A meter constructed according to this invention consists of a small motor,
actuated by current from the said working circuit, and adapted (through the inter-
vention of a train of wheels) to indicate the energy expended-in any desired
units by means of index fingers moving over suitably marked dials.
The working principle of the motor is the known one of the rotation of currents

page_text: by magnets, experimentally shown by Faraday, and this present invention con-
stitutes improvements upon a former invention for which Letters Patent were
granted to me, dated 2nd October, 1889, No. 15,489.
In the accompanying drawings,
Fig. 1 is a front elevation of a meter, showing the dial face, but with the relative
positions and dimensions of the train of wheels and pinions indicated by dotted
Îines.
Fig. 2 is a side elevation, Fig. 3 is a plan, Fig. 4 is a longitudinal section, Fig. 5
is an elevation of an iron cylindrical magnet extension, showing the relative
position of the armature by dotted lines; and
Fig. 6 is a plan of a ring clip on the said magnet extension.
Similar letters of reference indicate similar parts throughout the figures.
The cylindrical armature a is of aluminium, (or copper), vertically supported
between jewelled pivotal bearings and c which are properly insulated. A horse
shoe electro magnet is provided and fixed upon a base d of wood, slate or other
non-conducting material, and the lower limb of the magnet e is secured thereto.
Both the lower limb e, and the upper limb f, of the magnet are made of flat soft
iron, and are connected together by a turned yoke or stud a which also forms the
core of the exciting coil . A circular hole is bored through the polar ends of
the magnet limbs e and f, and a circular or cylindrical iron extension i is fitted to
the bottom one e, which extends upward into the hole in f. This upper hole is
large enough to provide for the enlarged extremity of the polar extension i, and a
narrow and truly concentric annular space surrounding the same in which the
armature a may rotate; and as the shell of the armature is very thin, a strong
magnetic field, truly annular and cylindrical in form, is obtained to act upon the
armature.
The polar extension i is bored out at its upper part to form a tube to receive a
central mercury trough j (properly insulated), in which is the lower pivotal
bearing of the armature a. The armature axle is bored cup shaped at the bottom
to receive the jewel for the lower pivot, and the space thus formed is made
sufficiently deep to form a small air chamber. This air chamber (by the com-
pression of air therein) serves to protect the lower pivotal bearing from actual
contact with the mercury, and consequently both the bearing and the mercury are
kept clean. As the armature axle is of an appreciable size it follows that the
mercury in the central mercury trough surrounds the axle and, together with
the mercury in the outer annular trough k, (at the bottom of the armature), exerts
a buoyant effect on the armature and which, by regulating the immersion, may be
made to balance the weight thereof and thus to reduce the friction from that source
to a minimum.
The lower and outer mercury trough k is of iron, of an annular form, and screwed
with a fine thread in the bore. This is made to screw upon a correspondingly
screwed section of an insulating tube of vulcanite or vulcanized fibre, fitted upon
the central part of the polar extension i. By screwing the annular trough k up or
down upon the tube 1, the dip of the armature a in the mercury is increased
or reduced as required Around the trough k is a brass ring clip m which is
secured upon the trough by screwing together the open ends of the clip. The
circuit connection is made from a terminal n to the clip m, so that by screwing the
latter tight, good electrical contact is made with the mercury trough k, through
the armature a, central mercury trough j, which is connected with the other
terminal o by an insulated conductor p carried through the centre of the polar
extension i. Surrounding the upper portion of the trough k, and resting upon the
clip m, is a ring of insulating material having an overhanging lip closely con-
forming to the armature a, which keeps the mercury in position whenever the
meter is out of level. The clip m further serves to keep the trough from moving
when properly adjusted.
The upper portion of the armature axle is provided with a worm c¹ for
actuating a worm wheel, pinion c², and train of wheels c³, c³, carried by a frame

page_text: work (as shown in Fig. 2); the outward or dial face of which is covered with
glass s (as shown in Fig. 4) for protection. The frame work ", with its train of
wheels being self-contained, can be removed bodily from the polar ends of the
magnet; and by the removal of the overhung bearing, the armature can be lifted
out clear of its mercury contacts for inspection or otherwise, as required.
With the solid iron magnet limbs shown, the meter is adapted for continuous
currents, but if required for alternating currents, the magnet is built up of
laminated plates in the manner well known. It is adapted for measuring watts (or
energy) with a compound winding upon the coil ; or for a current meter by a
series winding; for-as the electro motive force rises or faits so does the current
rise and fall (assuming the resistance of the circuit to be unaltered)-and I find
that the rotation of the armature and therefore of the index fingers is proportionate
thereto.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. An electric meter, operating on the known principle of the rotation of currents
by magnets, comprising an electro horse shoe magnet, having a polar extension
adapted to carry a pivoted armature, central and outer mercury contacts and circuit
connections, a train of wheels and indexes mounted in a framework upon the said
magnet, and driven from the armature axle, substantially as and for the purpose
herein described.
2. An electro magnet having a tubular ended polar extension from one limb
thereof, prolonged to within the pole of the other limb, with a narrow annular space
adapted for the rotation of an armature between the two substantially as and for
the purpose herein described.
3. An armature pivotally suspended within a polar extension, adapted to revolve
in a complete annular magnetic field and to make electrical contacts at its central
and outer circumferential parts, substantially as and for the purpose herein
described.
4. In an electric meter, the combination of a polar extension, a central mercury
cup fitted within the same, an armature pivotally suspended within and making
electrical contact with the said mercury cup, an outer annular mercury cup adapted
for the rotation therein of the edge of the said armature and a cylindrical magnetic
field surrounding the said polar extension, substantially as and for the purpose
herein described.
5. In an electric meter, the c.mbination of a truly annular magnetic field of
force with an armature having a central mercury contact, and an outer annular
mercury trough adjustable to regulate the immersion therein of the armature,
substantially as herein described.
6. In an electric meter, the combination of a truly annular magnetic field of
force with an aluminium armature pivotally supported and having a central
mercury contact, and a circumferential mercury contact, and circuit connections,
substantially as and for the purpose herein described.
7. In an electric meter, the combination of a detachable self-contained frame-
work having a train of wheels and means for indicating desired units with the face
of a horse shoe magnet, an armature rotating in a truly annular magnetic field
produced in the said magnet, and a worm wheel, worm shaft and pinion for com-
municating motion to the said train of wheels from the axis of the said armature,
substantially as and for the purpose herein described.
Dated this 8th day of October 1891.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.