An Improvement in Electricity Meters.
Year: 1896

page_text: Date of Application, 22nd Jan., 1896
Complete Specification Left, 22nd Oct.. 1896-Accepted. 28th Nov.. 1896
An Improvement in Electricity Meters.
We, SIEMENS BROTHERS & Co. LIMITED and JOHN NEBEL of 12 Queen
Annes Gate, Westminster in the County of Middlesex, Electrical Engineers, do
hereby declare the nature of this invention to be as follows:-
This invention relates to the construction of an ammeter or volt meter, in such
a manner that it is light and simple, has but very small hysteresis error and is.
little liable to be influenced by neighbouring electrical conductors or machines.
To
For this purpose, a vertical coil of insulated wire, connected to the conductor
of the current which has to be measured, has passed down its central tube a.
rod of non-magnetic material the lower end of which is guided, preferably by
a roller travelling between two guide cheeks, and its upper end is jointed to an.
arm projecting from a rocking spindle, on which spindle is fixed an index.
the central rod are attached two or more iron wires bent to U form, each having
its one limb passing up the central tube of the coil and its other limb passing.
up outside the coil. The rocking spindle has an arm carrying a weight to.
balance the central rod and its U wires, and another arm carrying an adjustable.
weight to counterpoise the index to a certain extent. When a current passes
through the coil of the bobbin, the iron U wires are attracted upwards causing
the index to move over a graduated scale. When the instrument is to be used
as an ammeter the coil consists of a few turns of wire having low resistance.
When it is to be used as a volt meter the coil is one of high resistance,
preferably having in series with it a resistance which has a small temperature:
coefficient.
Dated this 22nd day of January 1896.
ABEL & IMRAY,
Agents for the Applicants.
Electricity meters.
We, SIEMENS BROTHERS & Co. LIMITED, and JOHN NEBEL, of 12 Queen
Anne's Gate, Westminster, in the County of Middlesex, Electrical Engineers, 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:-
This invention relates to a construction of an ammeter or voltmeter in such a
manner that it is light and simple has but very small hysteresis error and is little
liable to be influenced by neighbouring electrical conductors or machines.
We shall describe a meter according to this invention referring to the accom-
panying drawings.
Fig. 1 is a vertical section and Fig. 2 is a front view with part of the dial broken
away to shew the internal construction.
A is a vertical coil of insulated wire having its ends connected at B and C
or B and C to the conductor of the current which has to be measured. Down
Price di

page_text: the hollow centre of the coil A is passed a rod D of non-magnetic material the
lower end of which is guided preferably by a roller E travelling between two guide
cheeks. The upper end of D is jointed to a short arm projecting from a rock
spindle F on which is fixed an index I. The spindle F has a loaded arm G to
balance the rod D and its attachments, and another adjustably loaded arm H as
counterpoise to the index I. To the rod D there are attached at K two or more
iron wires L each of which is bent in form of a deep U and has one of its limbs
extending up the central hollow of the coil A, and its other limb extending upwards
outside the coil. When a current passes through the coil the wires L are attracted
upwards partly turning the rock spindle F and thus moving the index I more or
less along a graduated dial M. The coil A shewn in the drawings consists of a
few convolutions of wire or rod having low resistance, the instrument with such a
coil being employed as an ammeter. By substituting for the coil A a coil of high
resistance having a large number of convolutions the instrument is applicable as a
volt meter, in which case the coil should by preference have in series with it a
resistance having a small temperature coefficient. In order to avoid injury to the
delicate parts when the instrument is moved about the lower part of the rod D is
made to pass through a spring clamp N which holds it steady. When the instrument
is to be used, the clamp is opened so as to free the rod by screwing up a screw P
the coned end of which enters a coned hole formed in the limbs of the clamp N
spreading them apart.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
An electricity meter constructed and operating substantially as described with
reference to the accompanying drawings.
Dated this 22nd day of October 1896.
ABEL & IMRAY,
Agents for the Applicants.