Improvements in Apparatus for Measuring Electric Currents.
Year: 1889

page_text: Date of Application, 8th Feb., 1889
Complete Specification Left. 8th Nov., 1889-Accepted, 14th Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Measuring Electric Currents.
We, LUCIEN ALFRED WILHELMINE DESRUELLES of 8b Avenue Percior, Manufac
turer of Electrical Apparatus and RAPHAËL FENELON OVIDE CHAUVIN of 173 Rue
Legendre, Electrician, both of Paris, in the Republic of France, do hereby declare
the nature of this invention to be as follows :-
The galvonometer apparatus constructed according to the said invention is devised
for the purpose of augmenting the amplitude of deviation of the parts employed for
measuring electric currents and for obviating the variations to which the said parts
have been subjected, and which injuriously affect the exactitude to a greater or less
degree.
Our galvanometer (volt-metre or ampere-meter) comprises a cylindrical bobbin
upon which inore or less thick wire is wound according to requirements, and in which
is contained a volute a of thin sheet iron, the development of which prosents the form
shown in Figure 1.
Figure 2 is a plan and
Figure 3 a side elevation of the said volute.
As shown in Figure 2, the rectangular portion of the strip of thin sheet iron is bent
in such a manner that its edge b occupies vertically the generatrix of the volute, the
latter being contained and fixed in the bobbin. A small rectangular plato c consisting
also of thin sheet iron is arranged as shown in Figure 4 upon the rectangular part
of the volute and can turn in the latter, being mounted upon a vertical axis which
passes through the generatrix of the volute, along the edge of its rectangular part.
The aforesaid plate can move away from the latter part in a similar manner as a leaf
of a book by turning upon its axis. This takes place when an electric current passes
through the wire wound upon the bobbin. At this moment the volute and the movable
plate are magnetized and obtain a polarity of the same name so that the movable
plate will move away from the rectangular part of the volute with an energy corre-
sponding to the strength of the current. A spiral spring fixed to the axis of the
movable plate serves to oppose the action of the current, and causes the movable plate
to return to its original position when the current ceases to act. An index connected
with the movable plate indicates the deviations upon a dial plate fixed upon the upper
part of the bobbin and the whole is contained in a box closed by a glass plate which
enables the deviations of the said index to be observed.
1050
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Measuring Electric Currents.
We LUCIEN ALFRED WILHELMINE DESRUELLES, of 8 Avenue Percier Manufac-
turer of Electrical Apparatus, and RAPHAEL FENELON OVIDE CHAUVIN, of 173 Rue
Legendre, Electrician both of Paris, in the Republic of France 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 :—
The galvanometric apparatus constructed according to the said invention is devised
for the purpose of augmenting the extent of deviation of the parts employed for
measuring electric currents and for obviating the variations to which the said parts
have been subjected, and which injuriously affect the exactitude to a greater or less
dearee

page_text: The invention is illustrated in the drawing loft with the provisional specification.
Our galvanometer (volt-meter or ampère meter) comprises a cylindrical bobbin
upon which more or less thick wire is wound according to requirements, and in which
is contained a volute a of thin sheet iron, the development of which presents the form
shown in Figure 1. Figure 2 is a plan, and Figure 3 a side elevation of the said
volute.
As shown in Figure 2, the rectangular portion of the strip of thin sheet iron is bent
in such a manner that its elge occupies vertically the generatrix of the volute, the
latter being contained and fixed in the bobbin. A small rectangular plate c con-
sisting also of thin sheet iron is arranged as shown in Figure 4 upon the rectangular
part of the volute and can turn in the latter, being mounted upon a vertical axis d
which passes through the generatrix of the volute, along the edge of its rectangular
part. The aforesaid plate can move away from the latter part in a similar manner as
a leaf of a book by turning upon its axis. This takes place when an electric current
passes through the wire wound upon the bobbin. At this moment the volute and the
movable plate are magnotized and obtain a polarity of the same name so that the
movable plate will move away from the rectangular part of the volute with an
energy corresponding to the strength of the current. A spiral spring fixed to the
nxis of the movable plate serves to oppose the action of the current, and causes the
movable plate to return to its original position when the current ceases to net.
index connected with the movable plate indicates the deviations upon a dial-plato
fixed upon the upper part of the bobbin, and the whole is contained in a box closed
by a glass plate which enables the deviations of the said index to be observed.
An
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is:-
First. A galvanometric apparatus for augmenting the extent of deviation of the
parts employed in the measurement of electric currents, and comprising a thin metallic
volute cut and mounted as described with reference to the drawing.
Second. In a galvanometric apparatus the combination of a coil with a volute
onclosed in the said coil, and in which can turn a metallic plate e mounted upon a
vertical axis d with a spring, as and for the purpose specified.
Dated this 8th day of November 1889.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicants.