IMPROVE- MENTS IN MEANS FOR REGULATING THE GENERATIVE CAPACITY OF DYNAMO OR MAGNETO ELECTRIC MACHINES
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford of No 42 Southampton Buildings
in the County of Middlesex Patent Agent for an invention of "IMPROVE-
MENTS IN MEANS FOR REGULATING THE GENERATIVE CAPACITY OF DYNAMO
OR MAGNETO ELECTRIC MACHINES' A communication from abroad by
Thomas Alva Edison of Menlo Park in the State of New Jersey United
States of America
"
PROVISIONAL SPECIFICATION left by the said Thomas John Handford at
the Office of the Commissioners of Patents on the 9th March 1882.
"
THOMAS JOHN HANDFORD of No. 42 Southampton Buildings in the County of'
Middlesex Patent Agent "IMPROVEMENTS IN MEANS FOR REGULATING THE
GENERATIVE CAPACITY OF DYNAMO OR MAGNETO ELECTRIC MACHINES a com-
munication from abroad by Thomas Alva Edison of Menlo Park in the State of
New Jersey-United States of America
The object of this invention is to provide simple and efficient means for
regulating the generative capacity of dynamo or magneto electric machines by
acting upon the commutator brushes or springs to move them away from and
towards the points of greatest difference in potential, or most effective generation-
This object is accomplished by a mechanisin which is both actuated and controlled
by the current generated.
For this purpose is used a double or single motor or motor-like mechanism,
connected with the cominutator brushes so as to move them together in one or the
other direction
The electric circuits to this mechanism supplied by the current generated are
made and broken by an electro-magnet also energized by the current generated by
the machine
In carrying out this Invention, the arms carrying the commutator brushes are
mounted on a yoke pivoted upon the journal box next to the commutator cylinder
and around the armature shaft-The yoke also carries a worm wheel, with which
LD...

page_text: engages a worm-Secured to this worm, are two ratchet wheels with teeth raking
in opposite directions-With these wheels engage two pawl bars carried by
armature levers-The lower ends of the armature levers engage with circuit makers
and breakers, which are pivoted, Y-shaped pieces playing between contact
screws, and making their forward contacts when the armature levers are retracted,
and their back contacts when such levers are drawn forward by their electro
magnets.
An electro-magnet (the controlling device) is placed in a multiple arc circuit
from the main conductors of the machine-A resistance is also placed in the same
circuit.
An adjustable shunt around more or less of this resistance as desired, has one
part connected with the Y-shaped circuit controllers, and the other part with the
armature lever of this controlling magnet.
The front and back contacts of this last armature lever are connected with the
coils of the two electro-magnets first mentioned, and from the other ends of these
magnet coils connections are made with the front contacts of the Y shaped circuit
controllers.
A spring arm is employed to determine the central position of the armature
lever of the controlling magnet.
When there is the desired degree of generation, to supply the translating devices
in circuit, the controlling armature-lever stands in a central position, leaving the
circuits to both of the vibrating mechanisms open, but a decrease or increase
beyond fixed limits, caused by a change in the number of translating devices or by
other reasons, produces a movement of the armature lever of the controlling magnet
and a closure of one or the other circuit to the vibrating mechanisms.
The mechanism in circuit operates continuously until the brushes are adjusted to
the desired point, when its circuit is broken by the controlling magnet.
Instead of these vibrating mechanisms; electro-dynamic motors may be used, of
the Pacinotti or other suitable type, connected the same as the vibrating mechanisms,
or a single electro-dynamic motor may be used connected by a speed-reducing
gearing with the commutator brushes. In the latter case, the controlling magnet
would be arranged to operate a circuit reverser, so that the motor would run in one
or the other direction or be stopped altogether.
The field or exciting magnet of the machine has its coils connected with the
main conductors of the machine, or this circuit may be supplied from an external
source-The translating devices are preferably placed in multiple arc or derived
circuits.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas John Handford in the Great Seal Patent Office on the
8th September 1882.
"
THOMAS JOHN HANDFORD of No 42 Southampton Buildings in the County of
Middlesex Patent Agent " IMPROVEMENTS IN MEANS FOR REGULATING THE
GENERATIVE CAPACITY OF DYNAMO OR MAGNETO ELECTRIC MACHINES a com-
munication from abroad by Thomas Alva Edison of Menlo Park in the State of
New Jersey United States of America
The said invention has for its object providing simple and efficient means for regu-
lating the generative capacity of dynamo or magneto electric machines supplying
lamps or other translating devices located in derived or multiple are circuits, by acting
upon the commutator brushes or springs to move them away from and towards the
points of greatest difference in potential or most effective generation This object
is accomplished by mechanism hereinafter described which is both actuated and
controlled by the current generated and is connected with the commutator brushes
so as to move them together in one or the other direction. The electric circuits to
this mechanism supplied by the current generated, are made and broken by an
electromagnet also energised by the current generated by the machine
In carrying out the said invention, the arms carrying the commutator brushes
are mounted on a yoke pivoted upon the journal box next to the commutator
cylinder and around the armature shaft. The yoke also carries a worm wheel with
which engages a worm. Secured to this worm are two ratchet wheels with teeth
respectively tending in opposite directions. With these wheels engage two pawl
bars carried by armature levers The lower ends of the armature levers engage
with circuit makers and breakers, which are pivoted Y shaped pieces playing
between contact screws, and making their forward contacts when the armature
levers are retracted, and their back contacts when such levers are drawn forward
by their electromagnets. An electro-magnet (the controlling device) is placed in a
multiple arc circuit from the main conductors of the machine. A resistance is also
placed in the same circuit An adjustable shunt around more or less of this
resistance as desired, has one part connected with the Y shaped circuit controllers,
and the other part with the armature lever of this controlling magnet
The front and back contacts of this last armature lever are connected with the
coils of the two electro-magnets first mentioned, and from the other ends of these
magnet coils connections, are made with the front contacts of the Y shaped circuit
controllers
A spring arm is employed to determine the central position of the armature lever
of the controlling magnet.
When there is the desired degree of generation to supply the translating devices
in circuit, the controlling armature lever stands in a central position, leaving the
circuits to both of the vibrating mechanisms open but a decrease or increase beyond
fixed limits, caused by a change in the number of translating devices or by other
reasons produces a movement of the armature lever of the controlling magnet, and
a closure of one or the other circuit to the vibrating mechanisms The mechanism
in circuit operates continuously until the brushes are adjusted to the desired point
when its circuit is broken by the controlling magnet
In lieu of these vibrating mechanisms electro dynamic motors may be used of the
Pacinotti or other suitable type connected the same as the vibrating mechanisms
or a single electro-dynamic motor may be used connected by a speed reducing
gearing with the commutator brushes, the controlling magnet in the latter case

page_text: being arranged to operate a circuit reverser so that the motor will run in one or
the other direction or be stopped altogether.
And in order that the said Invention may be perfectly understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the two figures on the accompanying sheets of drawings
Fig 1 (Sheet 1) of the accompanying drawings shews a view partly diagrammatic
of mechanism constructed in accordance with the said Invention. Fig 2 (sheet 2)
illustrates the use of a single electro dynamic motor for the purpose, the motion of
the motor being controlled by an electro magnet located in a multiple are or
derived circuit
Referring to Fig 1 A is the armature of a dynamo or magneto electric machine
and B its commutator cylinder
The main conductors 1, 2, run from the commutator brushes a which are carried
by arms C secured to the pivoted yoke b but insulated therefrom by bushings d.
A worm wheel e is secured to the yoke b and engages with a worm e¹ secured to two
ratchet wheels ff having teeth respectively tending in opposite directions D¹ D'
are electro magnets, the armature levers h h of which carry pawl arms g g¹
engaging respectively with f, f¹ These levers which are pivoted at mm² are
retracted by springs, They are extended below their pivots and serve to throw
Y shaped circuit controllers n, n¹ the action being assisted by springs a 8' or weights
In a multiple are circuit 7, 8, are a controlling electro magnet E and resistance G.
The adjustable shunt 5, 6, runs to the armature lever F and to the Y shaped circuit
controllers n n¹ The front and back contacts i¹ of F are connected with D D¹
which are also connected with the front contacts o o' of the circuit controllers n. n.
The spring arm p and stop p₁ determine the central position of F
The apparatus operates in the following manner :-
When the electromotive force of the current in 1, 2 is normal, and the candle
power of the lamps is at the desired point, the lever F will be held in a central
position breaking both divisions of the shunt 5, 6 as shewn in the drawing. An
increase in the electromotive force will cause the magnet to strengthen and
draw F against i closing the circuit through D. The lever h is then caused to
vibrate the circuit being alternately broken by the electro-magnet attracting the
lever hand thus throwing over the circuit controller n to one side, and made by
the retractile action of the spring drawing back the lever h and thus throwing
the circuit controller n to the opposite side. The vibration of this lever through
the pawl h and ratchet wheel the worm e¹ and the worm wheel e will move the
brushes away from the line of maximum generation until the normal candle power
is restored, when lever F will assume a central position under the action of the
devices herein before described. A decrease in electromotive force, will weaken E
further allowing F to rest upon the contact and closing the circuit through D'
This will have the effect of vibrating lever h¹ which through the pawl gland
ratchet wheel f' and the worm gear will adjust the commutator brushes towards
the line of maximum generation. The restoration of the normal candle power will
cause F, to again assume a central position as shewn in the drawing breaking both
divisions of the shunt and making both vibrating motors inactive.
It should be observed that in practice it is found indispensable to use means for
determining the central position of the lever F under approximately normal
conditions of the current as otherwise a flickering and unsteadiness in the lights
will result.
In figure 2 a single revolving electro motor is shewn as employed to shift the
brushes the direction of revolution of the motor armature being changed by
reversing the polarity of the current flowing through the field circuit. H is the
revolving armature of the motor and I, I', the cores of the field magnet, which
cores are shewn in horizontal section as are the cores of the generator field magnet.
The armature shaft of the motor has a worm which engages directly with the
worm wheel e attached to and moving the yoke b which carries the commutator
brushes a a of the generator A. The electro magnet E in the multiple arc

page_text: circuit 7, 8 has its armature lever F arranged to throw the spring arms K L of the
current reverser away from the intermediate block M
A multiple are circuit 9, 10 is provided with resistance G, around which there
is a shunt circuit 56 through the armature and field coils of the motor. One
commutator brush q of the motor is connected with 9, 10, on one side of the
resistance G. while the other commutator brush is connected with the block M
The two ends of the wire of the field magnet of the motor are connected with
the spring arms K L whilst the armature lever F is connected with the other side
of the resistance G
It will be seen that the current will always flow in the same direction through
the armature coils no matter which spring arm is in contact with M while the
current will flow through the coils of the field magnet in one direction or the other
according to whether one spring arm or the other is in contact with M
The apparatus operates in the following manner viz:-
When the candle power of the lamps is normal the lever F will stand in a
central position balanced between springs t t and out of contact with K and L
breaking the motor circuit 5, 6. If the electromotive force increases lever F will
be attracted by magnet E and will make contact with K. pushing it out of contact
with M. The motor armature H will then revolve in the direction to move the
cominutator brushes a, a, of the generator A, away from the line of maximum
generation until the normal candle power is restored when F will again assume
a central position. If the electromotive force decreases magnet E will weaken and
the retractile spring of F will draw it back forcing L, from M and allowing K, to
remain resting against M. This causes the motor armature to revolve in the
opposite direction, and to shift the brushes, a a towards the line of greatest
generation. When the normal candle power is restored F will come to central
position and will break the motor circuit
In lieu of employing a single revolving electro motor two revolving electromotors
may be used connected in a similar manner to the vibrating mechanisms in the
apparatus herein before described with reference to Fig 1 so as to be controlled in
their motion by an electro magnet which is located in a multiple arc or derived
circuit and arranged so as to operate in the manner herein before described.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is:-
The combination with a dynamo or magneto-electric machine supplying lamps
or other translating devices located in derived or multiple arc circuits, of mechanism
actuated by the current generated for adjusting the position of the commutator
brushes or springs of the machine, for the purpose of regulating its generative
capacity, and of an electro magnet controlling such mechanism located in a multiple
arc or derived circuit, the whole being arranged and combined so as to operate
substantially in the manner hereinbefore described
In witness whereof I the said Thomas John Handford have to this my
Specification set my hand and seal this eighth day of September in the
year of our Lord One thousand eight hundred and eighty two.