IMPROVE- MENTS RELATING TO DYNAMO, AND MAGNETO ELECTRIC MACHINES FOR REGULATING THE GENERATION OF CURRENT BY SUCH 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 "IMPROVE-
MENTS RELATING TO DYNAMO, AND MAGNETO ELECTRIC MACHINES FOR
REGULATING THE GENERATION OF CURRENT BY SUCH MACHINES Com-
municated to me 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 21st August 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings, in the County of
Middlesex, Patent Agent "IMPROVEMENTS RELATING TO DYNAMO, AND MAGNETO
ELECTRIC MACHINES FOR REGULATING THE GENERATION OF CURRENT BY SUCH
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 object of this Invention is to provide simple and efficient means for
automatically regulating the generative capacity of dynamo or magneto electric
machines, supplying lamps, or motors arranged in multiple arc.
This regulating apparatus may be arranged to regulate for changes in the speed
of the engine as well as in the number of translating devices, and to keep the
candle power of the lamps constant and prevent flicker.
This
This is accomplished by providing a mechanism operated by the current generated,
and throwing resistance into and out of one of the main conductors
mechanism is controlled by an electro magnet located in a multiple arc circuit
beyond the resistance and affected exactly as are the lamps themselves by changes
in the speed of the engine, and in the number of lamps or motors in circuit, and
also by the throwing in and out of the resistance. When the lever of this magnet
makes its forward contact, a circuit is completed through the resistance adjusting
mechanism, and resistance is thrown into the main line or conductor, and when
this lever makes its back contact another circuit through the resistance-adjusting
.

page_text: mechanism is completed and resistance is cut out of the main line. When the
candle-power is normal the lever of the controlling electro-magnet is held in a
central position by spring fingers, or equivalent means.
The resistance adjusting mechanism is composed of two electro-magnets, whose
armature levers carry pawls engaging with two ratchet wheels, the forward
movements of which throw the contact arm in opposite directions. The divided
circuit running through these electro-magnets may be a multiple arc circuit, a shunt
circuit, or other circuit, having always when closed sufficient energy to work the
mechanisın.
This circuit passes through a circuit breaker common to both magnets, which is
preferably a mechanical circuit breaker operated by some moving part, and may
be a wheel riding on the armature shaft, and carrying a circuit breaking cylinder.
The field circuit of the generator is also a multiple arc circuit from the main
conductors, and is connected with such main conductors beyond the resistance, so
that it will be affected by such resistance, like the lamps and will receive more
current when resistance is cut out of the main line, and less current when resistance
is thrown into the main line.
When it is required to regulate only for changes in the number of translating
devices in circuit from the generator, the thermal effect of the current generated
may be used to vary the current energizing the field magnet.
This is accomplished by the use of a compound thermostatic bar, or one composed
of two metals cach having a different coefficient of linear expansion. This bar
forms part of the main circuit, and is secured rigidly at one end, and is moveable
at the other, the circuit being completed at the free end; by means of a. point
dipping in a mercury cup.
To the free end of the bar is secured an arm carrying a number of contact
points which dip into a series of mercury cups, the mercury in the cups being at
different levels, or the points of different lengths, so that when the arm is raised or
lowered the contacts are broken or made successively...
In the field circuit of the generator, which is preferably a multiple arc circuit
from the main line, is placed a series of resistances, around each of which is formed
a shunt circuit connected with a mercury cup; whereby the raising of the arm
and successive breaking of the mercury contacts, causes the resistances to be placed
in the field circuit, one after another; while the lowering of the arm and closing of
the contacts, successively closes the shunts, and removes the resistances from the
field' circuit.
The raising and lowering of the arm which carries the contact points, is caused
by the expansion, and contraction of the compound bar to which it is attached.
When the current passing through this bar is increased by the addition of
translating devices in the main circuit the unequal expansion of the two metals
'occasioned by the increased heat causes the bar to bend, and so lower the arm
which is attached to its end, and throw out resistance from the field circuit; and a
decrease in the number of translating devices, causing the bar to bend in the
opposite direction, places resistance in the field circuit.

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
20th February 1883.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS RELATING TO DYNAMO AND MAGNETO
ELECTRIC MACHINES FOR REGULATING THE GENERATION OF CURRENT BY SUCH
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 has for its object the provision of simple and efficient means
for automatically regulating the generative capacity of dynamo or magneto electric
machines, supplying lamps or motors arranged in multiple arc
One part of the said Invention relates to apparatus which will regulate for
changes in the speed of the engine as well as in the number of translating devices
and keep the candle power of the lamps constant and prevent flicker.
This is accomplished by providing a mechanism operated by the current
generated and throwing resistance into and out of one of the main conductors.
This mechanism is controlled by an electro magnet located in a multiple are
circuit beyond the resistance and affected exactly as are the lamps or motors
themselves by changes in the speed of the engine and in the number of lamps
or motors in circuit and also by the throwing in and out of the resistance,
When the lever of this magnet makes its forward contact a circuit is completed
through the resistance adjusting mechanism and resistance is thrown into the
main line or conductor; and when this lever makes its back contact another
circuit through the resistance adjusting mechanism is completed and resistance is
cut out of the main line or conductor. When the candle power is normal the
lever of the controlling electro magnet is held in a central position by spring
fingers or equivalent means.
The resistance adjusting mechanism is composed of two electro magnets whose
armature levers carry pawls engaging with two ratchet wheels, the forward move-
ments of which throw the contact arm in opposite directions. The divided circuit
running through these electro magnets may be a multiple arc circuit, a shunt circuit, or
other circuit having always when closed sufficient energy to work the mechanism.
This circuit passes through a circuit breaker common to both magnets which is
preferably a mechanical circuit breaker operated by some moving part and may be
a wheel riding on the armature shaft and carrying a circuit breaking cylinder.
The field circuit of the generator is also a multiple are circuit from the main
conductors and is connected with such main conductors beyond the resistance, so
that it will be affected by such resistance like the lamps and will receive more
current when resistance is cut out of the main line and less current when resistance
is thrown into the main line.
This part of the said Invention is illustrated in Figure 1 of the accompanying
drawings which is a view partly diagrammatic, of apparatus embodying the same.
A is a dynamo or magneto electric machine from which run the main con-
ductors 1, 2, in multiple arc circuits 3, 4 from which, are arranged the lamps (for
example) B. R is the resistance which may be located in either 1 or 2 but is
represented as located in 2 between the lamps and the generator. This resistance
is thrown into and out of circuit by the arm a which is moved in one or the other
direction by two ratchet wheels one of which is shown at b. CD are electro
magnets the armature levers c d of which, carry pawls ef working the ratchet
wheels. E is an electro magnet in a multiple are circuit 5. 6 connected with 1, 2
beyond the resistance R. The armature lever g is in another multiple arc
circuit 7, 8 which is divided at the front and back contacts hi of this lever;
the divisions of this circuit pass through the coils of the two electro magnets C. D.
and are again joined. The lever g is held in a central position by spring fingers k

page_text: The retracting spring 1 of the lever g is made adjustable so that the candle power
of the lamps may be adjusted at this point. The circuit 7. 8 has arranged in its
line a mechanical circuit breaker which may be a wheel m riding upon the
armature shaft n a detached portion of which is shown for clearness of illustration;
the wheel m carries a breaking cylinder o composed of metal and insulation upon
which cylinder rest spring fingers pq. The circuit wires run to these spring
fingers, the revolution of the cylinder alternately making and breaking the
electrical connection between such fingers.
In the condition of the parts represented in the drawings the lever g is held in
its central position by the spring fingers k the candle power of the lamps being
normal. When the current increases to a definite extent the lever g will make its
front contact / completing circuit through C and causing its lever c to vibrate with
the assistance of the circuit breaker. This movement will through the inter-
vention of the pawl e turn the ratchet wheel and thence the arm a so as to throw
more of the resistance into the main line or conductor until the candle power of
the lamps becoming normal the lever g resumes its central position breaking the
circuit 7-8. Upon a definite decrease of current the lever 9 will make its back
contact i energizing D and vibrating the lever d with the assistance of the circuit
breaker. The pawlf will then actuate its corresponding ratchet wheel and move
the arm a so as to cut resistance out of the main line or conductor until the candle
power of the lamps again becomes normal when the lever g will resuine its central
position as before.
The field of force circuit of the machine is a multiple are circuit 9, 10 from 1, 2.
the connection being made beyond the resistance R as shown so that it will bo
affected by such resistance like the lamps and will receive more current when
resistance is cut out of the main, line and less current when resistance is thrown
into the main line.
Another part of the said Invention relates to an apparatus which regulates only
for changes in the number of translating devices in circuit from the generator. In
this apparatus the thermal effect of the current generated is used to vary the
current energizing the field magnet.
This is accomplished by the use of a compound thermostatic bar, or one composed
of two metals each having a different coefficient of linear expansion. This bar
forms part of the main circuit, and is secured rigidly at one end and is movable at
the other, the circuit being completed at the free end by means of a point dipping
in a mercury cup.
To the free end of the bar is secured an arm carrying a number of contact points
which dip into a series of mercury cups, the mercury in the cups being at different
levels or the points of different lengths so that when the arm is raised or lowered
the contacts are broken or made successively.
In the field circuit of the generator, which is preferably a multiple are circuit
from the main line, is placed a series of resistances around each of which is formed
a shunt circuit connected with a mercury cup, whereby the raising of the arm and
successive breaking of the mercury contacts causes the resistances to be placed in
the field circuit one after another; whilst the lowering of the arm and closing of
the contacts, successively closes the shunts and removes the resistances from the
field circuit.
The raising and lowering of the arm, which carries the contact points is caused
by the expansion and contraction of the compound bar to which it is attached.
When the current passing through this bar is increased by the addition of trans-
lating devices in the main circuit the unequal expansion of the two metals
occasioned by the increased heat causes the bar to bend and so lower the arm
which is attached to its end, and throw out resistance from the field circuit, and a
decrease in the number of translating devices, causing the bar to bend in the
opposite direction places resistance in the field circuit.
This part of the said invention is illustrated in Figure 2 which represents the
same partly in diagram.

page_text: A is a dynamo electric machine having main conductors 1, 2, extending
therefrom, on which lamps or other translating devices a a are placed in multiple
arc circuits 9, 10. 3, 4 is a multiple are circuit which includes the coils of the field
magnet of the machine. In this circuit are placed resistances B, B1, B2, B³.
C is a compound thermostatic bar placed in the line of the main conductor 2 and
secured rigidly at one end b, but free at the other end, where is attached an arm D
carrying contact points c, c¹, c³, c³, of different lengths which enter cups d d con-
taining equal quantities of mercury; or the points themselves may be of the same
length, and the cups contain different quantities of mercury. At its free end the
thermostatic bar C has a point e dipping constantly in the mercury of a cup E.
Wires 5, 6, 7, 8 run one to each of the mercury cups d forming shunt circuits
around the resistances in the field circuit.
The raising and lowering of the arm D which carries the contact points, c c², c², c³,
is caused by the expansion and contraction of the compound bar Ċ to which it is
attached. When the current passing through this bar is increased by the addition
of translating devices in the main circuit the unequal expansion of the two metals
occasioned by the increased heat causes the bar to bend and so lower the arm D
which is attached to its end and by making contacts at the oups d throw out
resistance from the field circuit and a decrease in the number of translating devices
causing the bar to bend in the opposite direction by breaking the contacts places
resistance in the field circuit the generative capacity of the machine being thus
regulated.
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-The combination with a dynamo or magneto electric machine of translating.
devices, located in multiple arc circuits from its main conductors, an adjustable
resistance in one of such main conductors, and an electro-magnet located in a
multiple arc circuit and operating or controlling the operation of mechanism
throwing such resistance into and out of the main line, substantially as herein before
described.
Second: The combination with a dynamo or magneto electric machine, and
translating devices in multiple arc, of an adjustable resistance in one of the main
conductors, and the field of force circuit of the machine connected with the said
main conductor beyond such adjustable resistance, substantially as herein before
described.
Third The combination with a dynamo or magneto electric machine and trans-
lating devices arranged in multiple arc, of means operated by the thermal effect of
the current generated for varying the resistance in the field circuit of the machine,
substantially as hereinbefore described.
Fourth-The thermostatic bar located in the main circuit and operating on
variations in the number of translating devices in circuit to make and break
successive contacts thus varying the resistance in the field circuit of the machine,
substantially as hereinbefore described.
In witness whereof I the said Thomas John Handford have hereunto set my
hand and seal this nineteenth day of February in the year of Our Lord
one thousand eight hundred and eighty three.