IMPROVEMENTS IN OR RELATING TO DYNAMO OR MAGNETO-ELECTRIC MACHINES
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford of 42 Southampton Buildings
in the County of Middlesex Patent Agent for an Invention of "IMPROVEMENTS
IN OR RELATING TO DYNAMO OR MAGNETO-ELECTRIC MACHINES" Com-
municated to him from abroad by Thomas Alva Edison of Menlo Park in the
PROVISIONAL SPECIFICATION left by the said Thomas John Handford at
the Office of the Commissioners of Patents on the 5th August 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent " IMPROVEMENTS IN OR RELATING TO DYNAMO, OR
MAGNETO ELECTRIC MACHINES a communication to me from abroad by Thomas
Alva Edison of Menlo Park in the State of New Jersey United States of America
"
This Invention relates partly to means for deriving from a Dynamo or magneto
electric machine, two or more independent circuits, in which there will be different
electromotive force or pressure such circuits being adapted for independent
regulation.
The extra circuit (or circuits) has or have a lower electromotive force than the
main circuit, and is, or are designed more especially for use in energizing the field
of force magnet of the machine or for operating translating devices, of which
incandescing electric lamps form the best example, placed in multiple arc circuits,
and requiring a current of lower tension than the lamps or othe translating devices
in the main circuit: or this extra circuit may have both the magnet coils and the
lamps connected therewith in multiple arc.
The object is accomplished by arranging to bear upon the commutator cylinder
on each side of one of the main commutator brushes a secondary brush, which is
mounted so as to be capable of adjustment towards or away from the main brush
independtly of or together with its fellow on the other side of the main brush.
These two secondary brushes are connected together electrically and from them is
led one part of the secondary circuit the other part being connected with the main
brush on that side of the commutator cylinder. The farther apart the secondary

page_text: brushes are placed on opposite sides of the main brush, the greater will be the
tension of the current in the extra circuit, and hence the tension can be readily
regulated by varying the position of such brushes with reference to the main
brush. The tension of the current in the main circuit can be independently regu-
lated by shifting the main brushes or in any other suitable well known manner.
The connection of the secondary brushes together electrically does not short circuit
any of the coils of the armature, since currents are generated in the same
circumferential direction on both sides of the armature.
It is evident that in this manner two extra circuits may be derived from the
same machine instead of one, a set of secondary brushes being arranged to form a
circuit with each main commutator brush. In that case it will be seen that the
extra circuits themselves may be regulated independently of each other or together,
and may have currents of the same or different tension. It will also be under-
stood that one secondary brush instead of two may be used in connection with a
main brush to form each extra circuit, such secondary brush being mounted for
adjustment to and from the main brush forming the other pole of the extra circuit:
and in this manner almost any desired number of extra circuits may be derived
from one machine, the tension of the current in each depending upon the distance
of the secondary brush, from the main brush with which it is connected.
It is also evident that an extra circuit may be formed by placing two secondary
brushes on opposite sides of the commutator cylinder at points between the main
brushes, the secondary brushes forming the poles for the extra circuit and the
tension of the current in the extra circuit being dependent upon the position of
these brushes with relation to the line of neutralized generation.
The Invention further relates to means for automatically regulating the generative
capacity of a dynamo or magneto electric machine, when the extra circuit or
circuits, derived from the commutator cylinder as before described is or are used
alone to supply the field circuit of the machine.
For this purpose, the extra brush or brushes are mounted upon a pivotted or
turning yoke or arm, which is adjusted in its position by a mechanism operated
and controlled by the current generated.
This mechanism may be that described in the provisional specification lodged
with my application for Letters Patent dated 9th March 1882 No. 1142
If the vibrating mechanism described in the said provisional specification is used
each armature lever may serve to make and break the circuit of its own magnet,
or a revolving circuit breaker worked continuously by the armature shaft may be
placed in the circuit of both electro magnets
The extra commutator brush or brushes may be used either with or without
connection with one main commutator brush as herein before described.

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
5th February 1883.
"
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent IMPROVEMENTS IN OR RELATING TO DYNAMO OR
MAGNETO ELECTRIC MACHINES" A communication to me from abroad by Thomas
Alva Edison of Menlo Park in the State of New Jersey, United States of America
The said Invention relates to means for deriving from a continuous current
dynamo or magneto electric machine two independent circuits (viz. a main circuit
and an auxiliary circuit) in which there shall be different electromotive force or
pressure, such circuits being capable of independent regulation.
The auxiliary circuit has a lower electromotive force than the main circuit and
is designed for operating translating devices (of which incandescing electric-lamps
form the best example) placed in multiple arc circuits and requiring a current of
lower tension than the lamps or other translating devices in multiple arc in the
main circuit and the said auxiliary circuit has also by preference in multiple arc
the coils of the field of force magnet connected therewith or the said auxiliary
circuit may be emploved exclusively for supplying the field of force magnet, in
which latter case means are provided for automatically adjusting and controlling
the tension of the auxiliary circuit so as to regulate the generation of current by
the machine to suit the requirements of the main circuit.
In carrying out the said Invention there is arranged to bear upon the commutator
cylinder on each side of one of the main commutator brushes a secondary brush
which is mounted so as to be capable of adjustment towards or away from the
main brush, independently of or together with its fellow on the other side of the
main brush. These two secondary brushes are connected together electrically and
from them is led one part of the auxiliary circuit, the other part being connected
with the main brush on that side of the commutator cylinder. The farther apart
the secondary brushes are placed on opposite sides of the main brush, the greater
will be the tension of the current in the auxiliary circuit and hence the tension
can be readily regulated by varying the position of such brushes with reference to
the main brush. The tension of the current in the main circuit can be inde-
pendently regulated by shifting the main brushes, or in any other suitable well
known manner. The connection of the secondary brushes together electrically does
not short circuit any of the coils of the armature since currents are generated in
the same circumferential direction on both sides of the armature.
It is obvious that one secondary brush instead of two may be used in connection
with a main brush to form the auxiliary circuit such secondary brush being
mounted for adjustment to and from the main brush forming the other pole of the
auxiliary circuit.
It will thus be seen that whilst the main current has a tension due to the electro-
motive force of all or nearly all the coils of the armature the auxiliary current has
a lower tension due to the electro motive force of a part only of the coils whilst the
tension of the two currents is capable of being regulated independently.
When the auxiliary current derived from the commutator cylinder as before
described is used only to supply the field circuit of the machine means are pro-
vided for automatically adjusting and controlling the tension of the auxiliary
current and thus regulating the generative capacity of the machine by varying the
position of the secondary brush or brushes relatively to the main brush by a
mechanism operated and controlled by the current generated as hereinafter fully
described.

page_text: 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 several figures on the accompanying sheet of drawings the same letters of
reference indicating corresponding parts in all the figures.
Figure 1, is a view, partly diagrammatic illustrating one mode of carrying
out the said invention the secondary brushes being mounted for simultaneous
adjustment.
Figure 2 is a view illustrating a similar arrangement but with the secondary
brushes mounted so as to be independently adjustable and
Figure 3 is a view partly diagrammatic of apparatus for automatically varying
the position of the secondary brush or brushes relatively to the main brush, when
the extra circuit includes the coils of the field of force magnet for the purpose of
adjusting and controlling the tension of the auxiliary current and thus regulating
the generative capacity of the machine.
Referring to Figures 1 and 2 A is the armature B the commutator cylinder and
C the field of force magnet of the machine DD' are the main commutator brushes
which are mounted so as to be adjustable upon the c. minutator cylinder. From
these brushes run the main conductors 1, 2. in multiple arc or derived circuits 3, 4,
from which, are the lamps or other translating devices a. E E are secondary
commutator brushes which bear on the commutator cylinder on opposite sides of
the main brush D. From the secondary brushes E E' and the main brush Di
runs the auxiliary circuit 5, 6, The coils of magnet C and limps or other
translating devices are in multiple arc or derived circuits 7, 8 from the con-
ductors 5, 6. These translating devices do not require a current of so high a
tension as that required by the translating devices a. In figure the secondary
brushes E E' are shown as carried by a pivoted arm c so that they can be adjusted
together towards and away from the main brush D¹. In figure 2 they are carried
by separate and independently adjustable arms d d¹.
A single secondary brush may be used (in lieu of two secondary brushes electrically
connected to form one pole for the auxiliary circuit 5, 6, the other pole being
formed by one of the main brushes.
It is evident that as one of the main commutator brushes forms one pole of the
auxiliary circuit it is only necessary in operating lamps or other translating devices
in the auxiliary circuit to run out one main conductor, the conductor running
from the main commutator brush which forms the other pole of the auxiliary
circuit being used for one half of the auxiliary circuit as well as for one half of the
main circuit.
The lamps or other translating devices may be supplied alone by the auxiliary
circuit, or the auxiliary circuit may include also the coils of the field of force
magnet as shewn in Figures 1 and 2 or it may be used exclusively for supplying
the field of force inagnet. When the latter arrangement is adopted the means
illustrated diagrammatically in figure 3 are employed for automatically adjusting
and controlling the tension of the auxiliary current and thus regulating the
generative capacity of the machine by varying the position of the secondary brush
or brushes relatively to the main brush which forms the other pole of the auxiliary
circuit such means being operated or controlled by the current generated
The arm & carrying the secondary brush E has secured to it a spur wheel f
with which engages another spur wheel keyed to the same spindle g' with two
oppositely turned ratchet wheels, one of which is shewn at h. With these ratchet
wheels respectively engage two pawls i, k, carried by the armature levers lm of
electro magnets C³, D2, the levers being retracted by springs l, m¹, The circuit of
these electro magnets may be a circuit derived in any suitable way from the con-
ductors supplied by the machine. It is shown as a multiple are circuit 7, 8 from
the main conductors 1, 2 This circuit passes through the armature lever n of an
electro magnet E¹ the circuit being divided at the front and back contacts o. p. of
this lever and the magnets C2, D2, being located in the separate divisions of the
circuit. The circuit 7, 8 also passes through a circuit breaking wheel q driven by

page_text: the armature shaft r or any other moving part. The spring fingers s, t, rest on the
breaking hub of this wheel, and the circuit connections are made with these spring
fingers The electro magnet E' is located in a multiple arc circuit 9, 10, from 1, 2
Its armature lever n is retracted by an adjustable spring u and is held at a central
point intermediate between its contact points by spring fingers v
When the current increases to a definite extent the lever n of E¹ will make its
front contact o completing circuit through D³ and causing its lever m to vibrate
with the assistance of the circuit breaker q. This movement will, through the
intervention of the pawl k and gearing hgf, turn the secondary brush carrier d
and move the secondary brush E on the commutator cylinder nearer to the main
brush D' which forms the other pole of the extra circuit.
When the candle-power
of the lamps becomes normal the lever n will resume a central position breaking
the circuit 7. 8, this being the position shewn in the drawings. Upon a definite
decrease of current the lever n will make its back contact p energizing C and,
through the intervention of lever pawl i and gearing h, g. f, throwing the
secondary brush E further away from the said main brush D¹ whereby the required
regulation will be effected.
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 :-
First Deriving from the same commutator cylinder of a continuous current
dynamo or magneto electric machine, a main current having a tension due to the
electromotive force of all or nearly all the coils of the armature, and an auxiliary
current having a lower tension due to the electro motive force of a part only of the
coils of the armature, means for adjusting the tension of the two currents inde-
pendently of each other, and lamps or other translating devices requiring currents
of different tension arranged in multiple arc in the circuits of the two currents,
substantially as hereinbefore described.
Second A continuous current dynamo or magneto electric machine supplying
from the commutator cylinder a main current having a tension due to the electro-
motive force of all or nearly all the coils of the armature, and an auxiliary current
having a tension due to the electro-motive force of a part only of the coils of the
armature as set forth, the said auxiliary current including the coils of the field of
force magnet and having its tension automatically adjusted and controlled by
means substantially as herein before described with reference to Figure 3 of the
accompanying drawings.
In witness whereof I the said Thomas John Handford have hereunto set my
hand and seal this fifth day of February in the year of our Lord One
thousand eight hundred and eighty three.
THO³. J. HANDFORD. (L.S.)