Improved Means for Regulating the Action of Dynamo Electric Machines.
Year: 1885

page_text: Improved Means for Regulating the Action of Dynamo Electric
Machines.
We LOUIS JOHN CROSSLEY of Halifax in the County of York, Engineer, and
WALTER THOMAS GOOLDEN and ALEXANDER PELHAM TROTTER, both of Victoria
Mansions in the City of Westminster, Electrical Engineers do hereby declare the
nature of this invention to be as follows:-
This invention relates to improvements in the means and apparatus employed for
driving dynamos from sources of power whose motions are irregular and are occa-
sionally reversed, and is especially applicable in the illumination of trains and steam-
ships where the dynamo is driven from the axle of the carriage or the shaft of the
engine.
For such purposes it is generally necessary to provide means for storing the elec-
tricity, such as secondary batteries, and for charging such batteries it is preferable to
use a dynamo whose magnets are excited by a derived current, such a dynamo being
called "shunt wound."
In our invention the dynamo is arranged to give the required electro motive force
at a certain minimum speed.
We provide a governor operating by centrifugal force, or by some other means, if
necessary, as when used on a ship, such as pumping a fluid into a reservoir. The
governor is preferably arranged to give uniformn displacements of a sleeve or of a
shaft for uniform increments of speed. The sleeve or shaft to which this displacement
imparted carries a spring or contact piece, which is in electrical connection with the
shunt wire, and is arranged to travel over the surface of a number of insulated metallic
strips connected together by means of wires of certain resistances. The first of these
strips is also in connection with one end of the shunt or magnet coil. The current is
intended to pass, as required, through the successive resistances, and through the
sliding spring, which, by its position, determines the amount of resistance thrown into
the shunt circuit. Were this contrivance not present, an increase of speed of the
motor would cause increased electro motive force to be produced by the dynaino. But
by the action of this invention, the increase of speed, acting on the governor, causes a

page_text: shifting of the sliding spring or contact maker, and the insertion of proportionate
increased resistance into the shunt or field magnet circuit of the dynamo. By properly
arranging the traverse of the spring contact maker to correspond with the varying
speeds of the motor, the resistance is so regulated that the electro motive force remains
constant.
In charging secondary batteries, it is of importance that the electro motive force of
the charging dynamo should be in excess of the electro motive force of the batteries,
and when, owing to the speed of the motor being below a certain minimum, the dynamo
would be unable to maintain the requisite electro motive force, we arrange that the
circuit shall be interrupted by the sliding contact maker.
In order that the dynamo may always be driven in a uniform direction, notwith-
standing the reversing of the direction of motion of the motor, we attach two pulleys
or clutches to the shaft of the dynamo by means of ratchets, or, preferably, friction
clutches acting by the jamming of steel rollers between a ring on the pulley and curved
cams on the shaft, and we drive these pulleys, one with an open, and the other with a
crossed belt, or by means of other reversing gear, thus ensuring that the direction of
the motion of the dynamo shall be uniform.
In some cases we allow the direction of the dynamo to be reversed, and we then
arrange the brushes or rubbers so that they will act equally well in whichever way the
commutator revolves, and the two methods we employ are the following:-(1) The
brush or rubber may be composed of fine wire gauze rolled into a flat mass
of the requisite thickness, and to prevent the fraying of the edges, we cut
the gauze from the sheet diagonally. The brush or roller is pressed against the
commutator in a radial direction, and springs are used to keep it constantly up to its
place. Another form of brush or rubber, which is applicable to a reversing commu-
tator, is one composed of strips of sheet copper or suitable metal, or of wire arranged
as in an ordinary brush, but placed obliquely in a plane passing through the axis of
the commutator, thus giving certain freedom for the elasticity of the strips or wires to
keep them up to their places. (2) Where it necessary that the brushes should have
a certain amount of lead, we arrange that the whole brush holder may have a requisite
amount of play, and as the dynamo revolves the one way or the other, the brush-
holders are carried forward or backward by the friction of the brushes against the
commutator, bringing them up to the required position.
Not infrequently it is desired to control a dynamo whose magnets are excited by the
main current, as in a circuit of arc lamps. We arrange the sliding contact maker in
such cases so as to shunt or divert part of the current from the magnets when the
speed rises, and in cases where the total work of the dynamo has to be kept constant,
we apply a combination of the above methods.
NEWTON & SON,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION,
Improved Means for Regulating the Action of Dynamo-electric
Machines.
We LOUIS JOHN CROSSLEY of Halifax in the County of York, Engineer, and
WALTER THOMAS GOOLDEN and ALEXANDER PELHAM TROTTER both of Victoria
Mansions in the City of Westminster, Electrical Engineers, do hereby declare the
nature of this invention and in what manner the same is to be performed to be par-
ticularly described and ascertained in and by the following stateinent :-
This invention relates to improvements in the means and apparatus employed for
driving dynamos from sources of power whose motions are irregular, and are occa-
sionally reversed, and is especially applicable to the illumination of trains, and steam-
ships, where the dynamo is driven from the axle of the carriage or the shaft of the
engine.
For such purposes, it is generally necessary to provide means for storing the elec-
tricity, such as secondary batteries, and for charging such batteries, it is preferable to
use a dynamo whose magnets are excited by a derived current, such a dynamo being
called "shunt wound."
In carrying out our invention, which is designed to maintain a steady and uniform
current or difference of potential under varying circumstances, we so arrange the
dynamo electric machine as to secure its efficiency at a certain minimum speed, and
we provide it with a governor which, as the rotation of the machine increases, will
throw gradually increased resistance into the shunt circuit, thereby preventing the
undue increase of electro-motive force of the machine.
The secondary batteries being connected with the main circuit, will receive any
surplus current which is not. required by the lamps in the circuit, and will give out
that current to the lamps when the speed of the dynamo machine falls below a given
point.
To compensate for the machine being driven in the reverse direction, when the
motor engine is reversed, we provide a rocking coupling bar, which, moving auto-
matically to a new position as the rotation of the axle of the armature is reversed, will
rectify, and thereby maintain, the course of the current unaltered.
In the accompanying drawing
Fig. 1 is a side elevation of a dynamo-electrical machine of the "Gramme" type,
arranged according to our invention, and
Fig. 2 is an end elevation of the same, the electrical connections and circuits being
represented diagrammatically.
In these Figures, A is the armature, mounted on the axle B. CC are the field
magnets secured to the standards D, and E is a resistance box of any approved con-
struction for putting a regulated resistance into the shunt circuit.
The armature axle B is prolonged to form the spindle for a centrifugal governor F,
which serves to operate a sleeve F¹, working over a feather on this spindle, and
carrying an arm F2. To the extremity of this arm are secured two insulated elastic
fingers, which are designed to travel respectively over a series of contact plates
G G*, coupled in the usual way to the coils of the resistance box.

page_text: H is the commutator. I I, I* I* are two pairs of insulated metal blocks fixed on
one of the end standards D, and so situated with regard to each other, and to the axle
of the armature, that a bar K, mounted loosely on the axle, may be free to oscillate
between them, so as to bring within the same circuit, in the manner to be presently
explained, the block I on the right hand side, with the block I on the left hand side.
or the block I on the left hand side and the block I* on the right hand side, within the
same circuit.
The blocks II are connected together by means of a wire, and also to one of the
collecting brushes of the commutator, and the blocks I* I* are similarly connected
together and to the other collecting-brush.
The coupling bar K, although free to rock upon its axle, is held tightly thereto by
spring pressure, which readily yields to allow of the axle turning freely while the bar
is quiescent in one or other of its two positions. is a lubricating box mounted
on the bar K, and containing a plunger which is caused to bear, by means of a coiled
spring contained in the box, tightly against the axle B, so as to ensure the rocking
of the bar K, on the reversal of the rotation of the armature axle. When the bar is
thus rocked into one or other of the positions of Fig. 2, its further motion will be
arrested, and the axle B will rotate freely, notwithstanding the slight pressure put
upon it by the plunger in the box k.
Attached to the opposite ends of this bar are the terminals of the main line wire,
which terminals, when in contact with one or other pair of blocks I I*, complete the
circuit,
•
LL, Fig. 2, indicate the lamps in the main circuit, and M the secondary or storage
battery, also in. the main circuit.
N is a switch controlled by the operator for making and breaking the main circuit,
and throwing a high or low resistance into the shunt circuit, as required.
1. 1. 1. indicate the wires composing the main circuit from the machine to the lamps
and the storage battery, and back to the machine, and 2, 2, 2 indicate the wires of the
shunt circuit for exciting the field magnets.
The insulated fingers ff* are each connected with the shunt wires through the
switch N; and the coils of the resistance box, which are each connected with their
respective plates G G*, are also connected with the shunt wire.
When the fingers ff* are at their starting points, the resistance box will be prac-
tically outside the shunt circuit, but as, through the increase of speed of rotation of the
machine, the sleeve F is traversed by the centrifugal governor F, those fingers will
be advanced in succession over the plates of the series G G*, bringing, at each advance,
an additional resistance coil within the shunt circuit.
Fig. 2 shows the switch N in a position which has cut out the lamps from the main
circuit, leaving the electric current from the machine to accumulate in the battery.
When set in this position, the high resistance coils are cut out from the shunt circuit,
and the low resistance coils thrown in. At this time, the finger f completes the shunt
circuit, the low resistance being thereby brought into the shunt circuit. This provides
for the increase of the energy of the field magnets. When, however, the switch is
moved into the dotted position, the lamps are thrown into the main circuit, the
finger f* in this case completing the shunt circuit through the high resistance coils, and
thereby modifying the current to the lamps...
To provide for the automatic cutting out of the dynamo-electric machine from the
main circuit, when its speed has fallen below its fixed minimum, we employ the cut
out arrangement indicated at O, Fig. 2.
This cut out consists of a solenoid included in the shunt circuit, and serving to close
a break in the main circuit against the counteracting weight of the closing piece carried
by the solenoid core.
When the current, through the decrease in speed of the dynamo electric machine,
unduly falls, the contact piece will drop out of action, and the machine will be thrown
out of circuit, leaving the lamps in connection with the battery, from which they will
now receive their supply of electricity, instead of the battery acting merely as a
regulator

page_text: On the rise of speed of the machine to its fixed minimum, the action of the solenoid
will be again set up, and the break which cut off the machine from the main circuit,
will be closed, thereby renewing the supply of electricity from the dynamo machine to
the lamps, and utilizing the secondary battery merely as a regulator.
Instead of employing the rocking bar K above described, for compensating for the
reversed rotation of the motor engine, we sometimes propose to fit to the axle of the
machine two band pulleys, connecting the same by friction or other clutches, which act
in the same direction. The kind of friction clutch which we prefer is that which acts
by the jamming of steel rollers between a ring on the pulley and curved cams on the
shaft.
These pullies we drive, one with an open, and the other with a crossed belt, and we
thus ensure that the direction of rotation of the dynamo machine shall be uniform.
Having now particularly described and ascertained the nature of our said Invention,
and in what manner the same is to be performed, we declare that what we claim is :-
1. The use of a centrifugal governor applied to shunt wound dynamo-electric
machines, and fitted as described for increasing or decreasing the resistance in the
shunt circuit of such machines, as and for the purpose set forth.
2. The arrangement above described for compensating for the reversing of the
direction of rotation of the dynamo-electric machine.
3. The arrangement above described for automatically cutting out the dynamo-
electric machine from the main circuit, and reconnecting it therewith.
NEWTON & SUN,
Agents for the Applicants.