Intensity of the Currents in Dynamo Electric Machines.
Year: 1886

page_text: Intensity of the Currents in Dynamo Electric Machines.
I, HERBERT JOHN HADDAN of 67 Strand, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention, a communication to me
from abroad by Francisco Vivó y Graells of Canuda 13,3° Barcelona, in the
kingdom of Spain, Manufacturer, 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 an apparatus for regulating the intensity of the electric
currents produced by dynamo or magneto-electric engines by adjusting their speed,
or number of revolutions, whenever the resistance of the circuit increases or
decreases.
Referring to the accompanying drawings:
Fig. 1 is a vertical section through A B and Fig. 2 represents a plan of the
apparatus. Fig. 3 represents on an enlarged scale one of the faces of the carrier
showing also the manner in which the wires are arranged for establishing the
connection with the amperometer, the dynamo and the resistance apparatus.
Fig. 4 is a side view of the same carrier and Fig. 5 shows the amperometer on a
larger scale.
The apparatus consists of two cones M N placed symmetrically. One of these
is first put in motion and drives the other by means of a belt A B and this latter
one transmits the movement to the dynamo-engine by any suitable mechanical
arrangement.
The symmetrical position of the cones regulate the speed, since the belt slides
along the surface of the cones, and the greater the circumference embraced of the
first, the less the circumference embraced of the second will be, and vice versa ;
with this arrangement, according to the position of the belt, the number of
revolutions of the dynamo will increase or decrease proportionally. The belt.is
guided on the cones by means of forks or guides H Hi fixed on a carrier that
moves on two spindles F F¹ placed parallel to the axes of the cones; these spindles
will turn continually in opposite directions, and cause the carrier to ride forwards
or backwards, when it works with one or with the other, according to the direction
in which either of the bolts is running.

page_text: This motion is obtained by means of electro-magnets I I¹ placed on the carrier.
When either of these electro-magnets act upon the lever m the respective end x x¹
of the latter engages in one of the spindles F F¹. This happens each time that the
electric currents acting on the electro-magnet become unequal in intensity.
The electric current actuating the electro-magnets of the carrier, may be the
same produced by the dynamo or a derived current or one produced by a special
engine.
In order to cause the current to pass through the one or other magnet when the
main current increases or decreases an amperometer is employed whose pointer by
its motion to the right or left closes the respective circuit which allows the current
to pass to one of the electro-magnets of the carrier.
The cone N is driven by the engine by means of a belt working round the
pulley E; E¹ is a loose pulley.
The cone M is placed at a suitable distance and transmits to the dynamo by
means of a pulley R the movement that it receives from the cone N through the
belt A B.
The forks H and H' are fixed on the carrier P. The carrier P is moved
horizontally by means of two spindles F F¹ and runs on the guides G and G¹.
The carrier has two electro-magnets I and I placed one opposite to the other
and resting upon a plate of a non-conducting material. The magnets put in
action a lever m provided with projecting ends x, x¹.
The lever m oscillates on
the pivot n.
The two spindles F F¹ are always in motion; the spindle F receives the
movement from a belt passing over the pulleys p and p¹, and transmits it to the
bolt F through the pinions g g¹.
As soon as the lever m introduces one of its ends xx¹ into the thread of the
spindle For F¹ the carrier is correspondingly moved forwards or backwards.
Each of the electro-magnets is provided with two metal springs 6 b¹ and B B¹,
on the lower ends of each of these there is a metallic brush that comes in contact
with the metallic flat rails a a¹ and a² a³ respectively; the current enters through
one of these rails and leaves through the other, after acting upon the electro-
magnet connected with it.
When the current does not act upon the electro-magnets of the carrier, this
must be eutirely stopped. This is done by means of the racks S and S' and the
catches T and T¹, these are attached to the spring v vl. This spring is fixed at
the centre with the spindle n bearing on the points x x¹ of the lever. When
the end of the lever rises the pivot a lifts up the catch T disengaging it from the
rack S. The catch T rests on the rack S¹ whose teeth are cut in such way as not
to hinder the movement of the carrier when it runs in the direction of the arrow
Fig. 4. But if in consequence of a variation in the intensity of the current, the
carrier should move in opposite direction to that shown in Fig. 4, for establishing
the uniformity, the movements would take place in a contrary way to that above
explained. When the carrier is at rest the catches gear in the racks and hinder
the carrier from moving until a current passes.
The current coming from the dynamo D feeds the lamps E¹. H³ is the point of
departure of a branch current governing the amperometer, joining the main current
again at the point H³.
A second branch current passes through the wire J and whilst the intensity of
the current H of the amperometer is normal, runs through the armature K and
contact spring r L to the electro magnet M¹. This current goes again in the
dynamo through N'. A closed circuit is produced so long as the intensity of the
current in H³ H³, is constant; but as soon as this increases or decreases the circuit
is open and a current is directed to the electro-magnets I or I¹ passing first through
the electro-magnet Q and the amperometer A'.
The amperometer A¹ shown in Fig. 5 is very much like those actually in use. It
differs only from these that the pointer B¹ is a little longer and is provided on the
end with a small blade mado of platinum or of any other metal bearing upon the

page_text: limits D' E' or FI G¹ which cause the pointer to take the position most convenient
to the normal resistance of the circuit. The points D E F G¹ may be placed on
the dial indicating the number of amperes to which the dynamo must work; in
Figs. 3 and 5 is shown an amperometer with a current oscillating between 13
and 14 amperes.
With this arrangement as soon as the continuous current in H' H³ increases or
decreases the pointer B₁ bears on the limit D' E' or F¹ G¹. In the first case the
blade C bearing against D¹ E¹ a new circuit will be formed whose current passes
first to the electro magnet Q and by means of the wire P P to the metallic rail a
through the contact spring ẞ and the electro magnet I¹ passes through the
opposite spring ẞ rail a³ and wire . In the second case the blade C coming in
contact with the points F G the current passes through the wire P P¹ rail a
electro magnet I rail a¹ and the wire i.
When the electric current passes through the electro magnet Q the armaturė
blade K is attracted and the current that acted on the electro-magnet M² is cut off
The sole object of the electro-magnet M' is to act as an apparatus of
resistance, this resistance being equal to the sum of the resistance of one of the
carriers electro-magnets and the resistance of the small electro-magnet Q.
at r.
If the electro-magnets I and I¹ were actuated by a current produced by any
other source instead of from the main current, in this case the resistance M¹ could
be dispensed with.
Having now particularly described an ascertained the nature of said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is:-
In the apparatus for regulating automatically the intensity of the electric current
produced by a dynamo by increasing or decreasing its speed:
1. The combination of two symmetrical cones, one of which is set in motion by
an engine and transmits the movement to the other which transmits it to the
dynamo. The said cones being geared by means of a belt guided automatically
upon the whole length of their surfaces, by means of guides or forks fixed in a
carrier moving along one or more spindles placed parallel to the axes of the cones,
all substantially as set forth.
2. The combination of two electro magnets actuated either by means of a
derived current, or by the main current, or by means of a current produced from
any source and which attract in opposite direction a lever m gearing with the
spindles upon which the carrier travels, all substantially as set forth.
3. The combination of an amperometer acting as a commutator-apparatus, with
a pointer adapted to some electric contact between two points placed on either
side of the point corresponding to the normal intensity of the current, in order
to close the circuit of one or other of the electro-magnets of the carrier, whenever
the intensity of the main current increases or decreases, substantially as described.
4. The combination of two racks placed one on each side of the carrier, with
the teeth cut symmetrically and in opposite direction in each of the racks with
a spring catch attached to the lever and gearing in the teeth of the racks all
substantially as set forth and for the purpose described.