Improvements in Instruments for Measuring Electric Currents and for Regulating and Controlling Dynamo Electric Machines and Prime Movers.
Year: 1887

page_text: Date of Application, 5th Aug., 1887
Complete Left, 7th May, 1888
Complete Accepted, 6th July, 1888
Improvements in Instruments for Measuring Electric Currents and
for Regulating and Controlling Dynamo Electric Machines and
Prime Movers.
We, WILLIAM LOWRIE, Engineer, of 117 Bishopsgate Street, London, E.C.,
CHARLES JAMES HALL, Electrician, of 1 Portland Road, Finsbury Park, London, N.
and HAROLD WERNER KOLLE, Electrician, of Egremont, Tulse Hill, London, S. W.
do hereby declare the nature of this invention to be as follows:-
Our invention relates to that class of instruments which utilize the thermal effects
of the electric current, and are therefore equally applicable to alternating and to
continuous currents.
Hitherto the variations of the length of a wire through which an electric current
is passed have usually been measured by rigidly fixing one end and attaching the
other to suitable multiplying and indicating mechanism. In order to obtain a more
sensitive instrument with a moderate length of wire, we use a wire suspended
between two rigid supports and apply to it, midway between the supports, a weight
or spring of such power as to compel the wire, when heated by the current, to form
an obtuse angle. The wire on either side of the weight or spring may be considered
as a radius of a circle having one of the supports as a fixed centre, and any variation
in length of the wire allows the weight or spring to move the apex of the angle to
the point where two circles struck from the fixed centres with the altered radii would
intersect. We thus obtain a maximum of deflection or deviation from the straight
line, and this deflection or deviation we cause to act on suitable multiplying and
indicating mechanism, or on mechanism for regulating or controlling dynamo electric
machines, or prime movers, or other motors.
The measuring instruments may be adapted to indicate, the tension or the quantity
of electric currents, and the mechanism for regulating or controlling dynamo
machines, motors, or prime movers is preferably not operated directly by the deflection
of the heated conducting wire, but by the intervention of strong direct currents or
other auxiliary power which is set in and out of action, or controlled, by the deflection,
of the said wire. The auxiliary currents may, for instance, act on electro magnets
adapted to regulate or control either the tension or the quantity of the current
produced by dynamo electric machines.
Dated this 4th day of August 1887.
FAIRFAX & WETTER,
433, Strand, London,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Instruments for Measuring Electric Currents and
for Regulating and Controlling Dynamo Electric Machines and
Prime Movers.
We, WILLIAM LOWRIE, Engineer, of 117 Bishopsgate Street, London, E.C.,
CHARLES JAMES HALL, Electrician, of 1 Portland Road, Finsbury Park, London, N.,
and HAROLD WERNER KOLLE, Electrician, of Egremont, Tulse Hill, London, S.W.,
do hereby declare the nature of this invention and in what manner the same is to
he performed, to be particularly described and ascertained in and by the following
statement
Our invention relates to that class of instruments which utilizes the thermal effects
of the electric current, and is therefore equally applicable to alternating and to
continuous currents.
Hitherto the variations of the length of a wire through which an electric current
is passed have usually been measured by rigidly fixing one end and attaching the
other to suitable multiplying and indicating mechanism. In order to obtain a more
sensitive instrument with a moderate length of wire, we use a wire suspended
between two rigid supports and apply to it, (midway between the supports), a weight
or spring of such power as to compel the wire, when heated by the current, to form
an obtuse angle. The wire on either side of the weight or spring may be considered
as a radius of a circle having one of the supports as a fixed centre, and any variation
in length of the wire allows the weight or spring to move the apex of the angle to
the point where two circles struck from the fixed centres with the altered radii, would
intersect. We thus obtain a maximum of deflection or deviation from the straight.
line, and this deflection or deviation we cause to act on suitable multiplying and
indicating mechanism; or on mechanism for regulating or controlling dynamo
electric machines, or prime movers, or other motors.
The measuring instruments may be adapted to indicate the tension or the quantity
of electric currents; and the mechanism for regulating or controlling dynamo
machines, motors, or prime movers is preferably not operated directly by the
deflection of the heated conducting wire, but by the intervention of strong direct
currents or other auxilliary power which is set in and out of action, or controlled, by
the deflection of the said wire. The auxilliary currents may, for instance, act on
electro magnets adapted to regulate or control, either the tension, or the quantity, of
the current produced by dynamo electric machines.
In the annexed drawings the same reference letters are used throughout the various
figures to denote the same part or parts having the same function. Fig. 1 is a
diagramatic representation of our invention as adapted to regulate and control a
dynamo electric machine A, (either alternating or continuous currents) the field
magnets of which are excited by the machine B.
Solenoids C, C¹ are arranged in combination with a regulator D, and an iron corę

page_text: within the said solenoids, so that when the top one C, is energized, the core is drawn
upwards and the plates are immersed deeper in the liquid by means of a cord passing
over a pulley d². Conversely, when the bottom solenoid is excited, the core is.
attracted downwards and raises the plates out of the liquid. This action of the
solenoid and its core, causes the liquid in the regulator D, (in which the plates dip),
to shunt current from the field magnets of the exciter B, and thus by reacting
upon the generator A, to keep the electro motive force of the latter constant.
At.
The wire E, is suspended between two rigid points of support, y, and z, and being
heated by the passage of the current, it expands and is deflected, as shown.
the centre part of the deflected wire E, is an insulated cord e to which is suspended a
dipping rod el, pivoted upon a point of support e, with a weight e³ to keep the rod
in equilibrium. When the wire E is heated by an excess of current and expansion
takes place, the suspended wire e¹ is lowered against its fulcrum e² and contact is
made with the plate c. This sets the upper solenoid C in force: the core is drawn further
into the interior of the solenoid, the plates in the regulator D are lowered; and
current is shunted from the exciter B; as already explained. Should the wire E
become unduly cooled, contact is made at the opposite end, e¹, instead of at c; which
sets into action the lower solenoid (1 and brings about decreased immersion of the
plates in the regulator D; with the result before stated. The coils of the regulator
are connected across the terminals of the exciter through the relay stops c and c¹.
A similarly suspended wire, F, to that already described as E, is arranged and
connected by an insulated cord to the dipping arm f¹, as a safety device; in case of
the breakage of the wire E. In this case, the dipping rod e¹ would immediately make
contact at c owing to the weight es bringing that end of the rod down. This, as
before explained, causes current to be shunted from the field magnets of the exciter.
An electrical connection, or arm, f2 is made from the pivotal end f¹ to the fulcrum e²..
If converters be used, in parallel, they are connected across the secondary
terminals, 21. This will maintain constant electro motive force in both primary and
secondary.
In the diagram Fig. 2, is shown a self excited dynamo machine for a series circuit.
The deflected wire E of the relay is in a shunt across a resistance G placed in the
main circuit. The main current passing round the regulator magnet coils. C and C,
one of them becomes short circuited by the relay according to the direction of the
current wave, in the manner already described. The result upon the generator A is
to keep the current constant.
Figs. 3 and 4 are front and end elevations respectively of the regulating apparatus;
the upper and lower solenoids being indicated by C and C. The iron core within is
shown by the dotted lines within the coils, and it is suspended by a cord over the
pulley and connected to the plates in the vessel D. These plates are insulated
from each other, (except through the water, which may be slightly salted or acidulated)
and connected to the circuit in the manner indicated by the diagrams. The plates
are preferably V shaped, so that a slight movement of the core produces a sensible
difference in the area of the plate immersion, and consequent resistance.
Fig. 5 is an elevation, and Fig. 6 a plan, showing the deflected wire E, suspending
cord e, dipping rod el contacts c and ef and safety device F, f, f2 and contact f³.
To the armis electrically connected the rod 2 through a support f*. Should
either E or F break the cooling of the unbroken wire contracts to break contact with
the regulator solenoids.
Adjusting screws h, h, are placed at the rigid points of support H, H, from which
the deflecting wires E and F are suspended.
Fig. 7, indicates our invention in its application to a measuring instrument. The
deflecting wire is caused to act upon an index pointer I by means of the cord e
passing around a pulley upon the axis of I. A spring i is adapted to keep the
pointer at zero when the wire is cold. It is adaptable as a Volt or Ammeter, and if
required for large electro motive force or current readings the same instrument may
be constructed with a number of wires which can be put in series or in parallel by
means of a commutator,

page_text: 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:
1. Measuring, regulating, or controlling electric currents or prime movers by
means of the expansion and deflection of an electrically heated wire fixed between
rigid points of support; substantially in the manner and for the purposes
described.
2. A measuring, regulating or controlling apparatus actuated by an electrically
heated and deflected wire or wires, operating for the said purposes either directly,
or by the intervention of an auxilliary power; substantially in the manner
described.
3. The combination of an electrically heated and deflected wire or wires, rigid
points of support for the same, a weight or spring applied at or about the apex of
the deflection, a moveable contact making rod, and one or more contact plates;
substantially as described.
4. The combination of an electrically heated and deflected wire or wires, rigid
points of support for the same, a weight or spring applied at or about the apex of the
deflection, and a multiplying or indicating mechanism substantially as described.
5. The combination of an electrically heated and deflected wire, a moveable contact
making rod or rods, one or more contact plates, and a variable resistance operating
directly or through an auxilliary force to regulate or control electric currents, or
prime movers; substantially as described.
6. The apparatus and arrangements shown or indicated by the figures from Fig. 1
to 7 inclusive; when operating substantially in the manner, and for the purpose
specified.
Dated this 5th of M 1000
FAIRFAX & WETTER,
433, Strand, London,
Agents for the Applicants.