IMPROVE- MENTS RELATING TO STEAM ENGINES AND THE OPERATION OF ELECTRICAL " GENERATORS THEREBY
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 STEAM ENGINES AND THE OPERATION OF ELECTRICAL
"
GENERATORS THEREBY Communicated to him 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 2nd October 1882.
"
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS RELATING TO STEAM ENGINES AND
THE OPERATION OF ELECTRICAL GENERATORS THEREBY a communication to me
from abroad by Thomas Alva Edison of Menlo Park in the State of New Jersey
United States of America,
In the Edison system of electrical distribution the dynamo electric machines
which supply current to the translating devices of a district are placed in multiple
arc relation to each other at a central station each machine being run by a separate
steam engine and the armatures being revolved directly by the engine shafts
without the interposition of belts or other gearing when high speed engines are
used, but with slow speed engines suitable belts or gearing or both are used to
multiply the speed.
In operating a number of dynamo or magneto electric machines arranged in
multiple arc relation to each other it is necessary that the machines should all
produce the same electro motive force, and in order that they should do this it is
necessary that their armatures should all be revolved at the same or practically the
same speed. In a multiple arc arrangement of electrical generators operated
by separate steam engines the governors of the independent engines having
independent movements and vibrating or jumping to a greater or less extent, the
generators must necessarily vary in speed and electro-motive force. This variation'
in speed and electro motive force results in an action peculiar to the multiple arc
arrangement of the generators, generators having lower speed and electro motive

page_text: force being driven as motors by the current from other generators and this relation
being reversed at intervals by the racing of the engines. Hence it is practically
impossible to operate generators in multiple are by means of separate independent
steam engines.
The object of this Invention is to obviate any difficulty of the kind.
One mode of accomplishing this object consists in so connecting the throttle
valve or cut off mechanisms of all the engines that any variations in the action of
such mechanism, produced either by the governor or by hand on one engine are
communicated to all the others, so that if the admission of steam to the chest or
cylinder of one engine is varied the same variation is produced in all the other
engines of the system.
The engines which it is preferred to use are those in which the steam is cut off
from the cylinder during a portion of each stroke of the piston, and the time of so
cutting off the steam is regulated by a centrifugal or other form of governor but
the invention is equally applicable to engines in which the admission of steam is
controlled entirely at the throttle valve.
In carrying out this portion of the invention one or more lines of connected
shafting are provided to which a number of arms are attached, each running to one
of the engines and there adjustably and removably connected with the throttle
valve or cut off mechanism in such a manner that a variation in the position of
such mechanism on one engine is communicated through the corresponding arm to
17 the shaft and thence to the throttle valve or cut off mechanism of all the other
engines connected with the said shaft
The variations of the valve or cut off mechanism may be accomplished solely and
automatically by the governors of the engines; or means may be employed at each
engine operated by hand for varying the cut off; such means may be employed in
connection with the governor; or the governor may be used simply as an indicator
of speed and the regulation effected solely by hand, a suitable indicating device
being employed in connection with the governor if desired, or the governor may be
dispensed with altogether and the regulation accomplished only by hand.
When the speed is regulated by hand the connecting shafting may be moved
directly by a hand lever and all the throttle, or cut off mechanisms adjusted
simultaneously or the connection with such shafting at any engine may be moved,
moving the shafting and the connections of all the other engines. Suitable friction
devices with or without counterbalancing weights or any positive locking device
with or without. friction devices or counter balancing weights are used to hold the
shafting in any position to which it is moved. The connection of each engine with
the shafting is made removable so that any engine can be disconnected therefrom
or connected therewith at will. This connection is also made adjustable in order
that each engine may be adjusted to work in unison with the others.
Or the object before mentioned may be accomplished by placing in a shunt
circuit from the main line into which all the generators feed a series of electro
magnets or solenoids one for each engine, each having a movable armature or core
and each of such armatures or cores being adjustably connected by suitable means
with the throttle valve or cut-off mechanism of an engine. An increase of current
in the main line caused by increase in the speed of the engines causes all the electro
magnets to increase in energy to the same extent, and the consequent movements.
of their cores or armatüres produce the corresponding variations in the throttle
valve or cut off mechanisms of the engines necessary to reduce their speed. It is
evident that all the engines will be simultaneously affected by this apparatus and
consequently that the same degree of speed will be maintained in all the said
engines.
Or instead of the magnets or solenoids an equal number of small electro-dynamic
motors may be used each having attached to its armature a spring of such strength
as to prevent the rotation of the armature when a normal amount of current is
passing but allow a movement in one direction to be made when the current
increases and draw the armature in the other direction on a decrease of current.
-

page_text: By suitable gearing and connections the movements of the armature are caused to
affect in the desired manner the valve or cut-off mechanism of the engine
With all the forms of apparatus hereinbefore described the dynamo or magneto
electric machines arranged in multiple arc are regulated in any of the known ways.
This is done preferably by an adjustable resistance in the field circuit of each
machine which is by preference thrown into and out of circuit by a hand operated
device.
The following apparatus may be used in combination with any of the arrange-
ments hereinbefore described :—
The field coils of the machines are in separate multiple are circuits from the
main line, and each of such circuits contains an adjustable resistance for regulating
the electro-motive force of the machine. In the present case each field circuit
contains an additional resistance besides the usual regulating resistance. This
resistance is varied by the movement of an arm which. is: operated by a spring
governor attached to the shaft or other revolving portion of the engine. When one
of the engines runs faster than the others the generator driven by such engine
gives an electro motive force greater than the others produce. But the increased
speed causes the spring governor to move the arm connected with the additional
resistance so as to place resistance in the field circuit of the machine, and reduce its
electro motive force to the proper point.
This device is preferably used as auxiliary to that in which all the cut off or
throttle valve.mechanisms are moved simultaneously by the governors or by hand
so that any variations in speed caused by friction or otherwise which are not
affected by the adjustment of the throttle valve or the cut off mechanism may be
counteracted by the adjustment of the additional resistance in the field. The device
may however be used in connection with any of the other arrangements herein before
described as before mentioned or separately or alone if desired.

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
31st March 1883.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS RELATING TO STEAM ENGINES, AND
THE OPERATION OF ELECTRICAL GENERATORS THEREBY." A communication to me
from abroad by Thomas Alva Edison of Menlo Park in the State of New Jersey
United States of America.
In the system of electrical distribution known as Edison's system the dynamo
electric machines which supply current to the translating devices of a district are
placed in multiple-arc relation to each other at a central station, each machine
being run preferably by a separate steam engine and the armatures being revolved
directly by the engine shafts without the interposition of belts or other gearing,
when high speed engines are used, but with low speed engines suitable belts or
gearing or both are used to multiply the speed.
In operating a number of dynamo or magneto electric machines arranged in
multiple arc relation to each other it is necessary that the machines should all
produce the same electro motive force and in order that they should do this, it is
necessary that their armatures should all be revolved at the same or practically the
same speed.
In a multiple arc arrangement, however, of electrical generators operated by
separate steam engines, the governors of the independent engines having inde-
pendent movements, or vibrating, or jumping to a greater or less extent, the
generators must necessarily vary in speed, and electromotive force. This variation
in speed and electromotive force results in an action peculiar to the multiple arc
arrangement of the generators, generators having lower speed and electromotive
force being driven as motors by the current from other generators, and this
relation being reversed at intervals by the racing of the engine. Hence it is
generally impossible to operate generators in multiple arc by means of separate
independent steam engines.
Now this Invention has for its object obviating any difficulty of the kind referred
to, and this object is accomplished in part by so constructing the throttle-valve or
cut-off mechanisms of all the engines that any variations in the action of such
mechanism produced by the governor on one engine are communicated to all the
others; so that if the admission of steam to the chest or cylinder of one engine is
varied, the same variation is produced in all the other engines of the system
The engines which it is preferred to use are those in which the steam is cut off
from the cylinder during a portion of each stroke of the piston, and the time of so
cutting off the steam is regulated by a centrifugal or other form of governor; but
the Invention is equally applicable to engines in which the admission of steam is
controlled entirely at the throttle valve.
Each generator is also provided with means for varying its electromotive force,
as required by the addition and removal of translating. devices, the governors being
employed to adjust the engines to meet the load and to secure uniformity of speed.
The means for varying the electromotive force of each generator, as required by the
addition or removal of translating devices may be an adjustable resistance in its
field circuit. In addition to the means for regulating the electromotive force of
the machine, in accordance with normal conditions, each field circuit contains an
additional resistance which is varied by the movement of an arm operated by a
spring governor, the latter being attached to the shaft or other revolving part of
the engine.

page_text: When one of the engines runs faster than the others, the generator driven by
such engine gives an electromotive force greater than the others produce, but the
increased speed causes the spring governor to move the arm connected with the
additional resistance, so as to place resistance in the field circuit of the machine
and reduce its electromotive force to the proper point. Any variations therefore
in speed caused by friction or otherwise, which are not affected by the adjustment
of the throttle valve or the cut-off mechanism are counteracted by the adjustment
of the additional resistance in the field. This device may however be used
separately from that in which all the cut-off or throttle valve mechanisms are
moved simultaneously by the governors.
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 sheets of drawings.
Figure 1 (Sheet 1) of the accompanying drawings is an elevation of parts of three
engines with a diagrammatic plan of their connections all arranged according to
one mode of carrying out the said Invention.
A. A. A. represent the bed plates: B, B, B the fly wheels: and C, C, C, the
centrifugal governors of the engines.
D, D, D, are the eccentrics which operate the inlet valves of the cylinder through
rods E, E, and the exhaust valves through rods F (such valves not being shown)
The rods E, E', are connected to the slide block a, in the curved slot b, and the
rod F directly to the eccentric: the eccentric being guided in its movement by the
vibrating lever G.
As is well understood, the movement of the governor balls c, c, acting through
arm l, and links d, d', varies the position of the slide block a, in the slot b, and
thus causes the slide-valves to cut off the steam more or less quickly according to
the rapidity of the revolution of such governor balls.
In the example represented in the drawings it is assumed that each engine
shaft O carries the rotating armature P of a dynamo electric machine, having field
magnets Q, but the armatures are shown diagrammatically separate from the engine
in the figure for clearness of illustration. These dynamo electric machines are in
multiple arc relation to each other, each armature P, being in a derived circuit 3, 4,
from the main circuit 1, 2,; and the field magnets of each machine being in a
derived circuit 5, 6, from the said. main circuit, or the field circuits 5, 6 may be
from a separate source of electrical energy. Each of the field circuits 5, 6, contains
a resistance R, made adjustable by means of an arm S. The object of these
adjustable resistances is to regulate the generation of current by the machine, for
changes in the number of translating devices in circuit in the district supplied by
the machines.
To the link d, of each engine is pivoted a lever H, terminating in a handle f.
From this lever extends upwardly a rod I, the upper end of which is attached to
an arm J, extending downwardly and outwardly from the shaft K. It will be
seen that the position of the slide block a, of an engine is changed by moving the
lever H while at the same time such movement of the lever H produces through
rod I, and arm J, a turning of the shaft K which moves all the other arms J,
rods I, and levers H, thus changing the position of the slide blocks a, of all the
engines.
From the shaft K, extend the arms L, downwardly, and in an outward direction
opposite to that of the arms J. Each arm L, carries a weight M, and such weights,
assist in the turning of the shaft when an arm J is raised. A weight N is placed
on each of the levers H, to assist in bringing the lever down; and the weights M,
and N, act together to assist in bolding the shaft K in any position in which it
may be placed. Frictional or other suitable devices may however be used for so
holding the shaft.
A removable and adjustable connection is made between each lever H, and its
rod I. A small rod g, attached to the lever H, fits in the end of the rod I, and is
clamped therein by a screw h; so that by loosening the said screw,
the connection

page_text: between the lever H, and the rod I, is severed, and the engine may either remain
disconnected or the lever H may be adjusted and the connection again made;
whereby each engine is made independently adjustable. This may of course be
accomplished in many other ways.
• A pointer i, attached to the arm 7, indicates on a scale j, the extent to which the
governor balls are thrown out, and the lever H is moved in accordance with these
indications.
A convenient mode of adjusting all the engines to the same speed, is to fix when
all the engines are disconnected from the shafting by marking the rod I, or by
setting a suitable gauge or indicator attached to the said rod, the point to which
the lever H is to be adjusted. When the first engine is connected and adjusted to
this point, and its cut-off also adjusted to the proper point, the shaft is turned to
the proper position; and in connecting the other engines it is necessary only
to adjust their rods g, to the same points on the rods I, when it will be seen that
all the cut offs will be placed similarly to the first one, and all the engines will run
at practically the same speed.
In addition to the resistance R for varying the electromotive force of each
generator as required by the addition and removal of translating devices, there is
provided in each field circuit 5, 6, a resistance R'; this is varied by the movement
of a contact arm a¹, consisting of the pivoted lever of a spring governor G' which
s either attached to the shaft O as shown or to a shaft driven therefrom.
At a mean speed the lever a¹ will be in contact with the central point of the
resistance R¹ as shown. Any increase of speed of one engine independent of the
others would ordinarily increase the electromotive force of the particular machine
beyond that of the others: This increase of speed however throws a further part
of the resistance R', into the field circuit of the machine, increasing the resistance
of the field circuit and counteracting the effect of the increase in speed. A decrease
of speed has the contrary effect throwing resistance out of the field circuit.
Thus it will be seen that the machines will always have the same electromotive
force, notwithstanding variations in the speed of the engines.
The Invention may also be carried out with the use of other than centrifugal
ball governors for acting upon the throttle or cut-off mechanisms as for example
by pivoted centrifugal spring weights carried by the fly wheel of each engine and
connected with a double or a single or simple eccentric mounted loose upon the
engine shaft. The sleeve surrounding the double or the single or simple eccentric
is connected directly with the valve rod, and the adjustment of such eccentric by
the weights varies the point at which the steam is cut off. When the eccentric is
double there is an adjustment of the outer part upon the inner part of the
eccentric, as well as an adjustment of the inner part upon the shaft, while if the
eccentric is single there is an adjustment only of the eccentric upon the shaft.
These modifications are illustrated in figures 2 to 8, (Sheet 2) of the drawings:
Figure 2 is an elevation of two engines, with the governor eccentrics connected
with a common shaft, a diagram of the connections being shown;
Figures 3, 4, and 5, are detail views drawn to a larger scale of the governor and
some of the adjacent parts, figures 3, and 4 being elevations of opposite sides and
Figure 5 an elevation at right angles thereto.
Figure 6 is a sectional view of a clutch forming the removable connection with
the common shaft.
A and B represent dynamo or magneto electric machines, which have their
armatures connected by wires 3, 4 to the same conductors 1, 2, or to the same
system of conductors.
C and D, represent steam engines, the shafts a, of which are coupled directly
with the shafts of the generators. Upon each engine shaft a, is a wheel E, which
carries two pivoted weights F, G. These weights are thrown inwardly towards
the shaft by springs b, and are connected by links c with the inner and outer
movable parts H, I of loose double eccentrics. If a single or simple eccentric is
used the links c will be connected with the one movable part. The eccentric

page_text: sleeve d is connected with the valve rod K. The automatic adjustment of the
eccentric by the weights varies the point at which the steam is cut off.
The eccentric, or the inner part H thereof is mounted on a sleeve L fitted on.
the shaft a, and carrying a pulley M. This pulley is connected by a belt N, with
a loose pulley O, on the revolving shaft P. The loose pulley O is connected with
the shaft P, when desired by a friction clutch Q (figure 6.).
All the engines (two or more) have their governors connected in this way with
the revolving shaft P, and are thus forced to work in unison; when the eccentric of
any one engine is adjusted under the action of its governor the eccentrics of the
other engines being simultaneously adjusted by reason of their connection with the
common controlling shaft P.
The field circuits 5, 6, of the machines are provided with adjustable resistances R
and movable arms S to regulate the machines as required by the addition and
removal of translating devices. In addition to the resistance R there is provided
a resistance R¹ in each field circuit 5, 6; this additional resistance is varied by the
movement of a contact arm a¹ consisting of the pivoted lever of a spring
governor G¹ which is either attached to the shaft a as shown or to a shaft driven
therefrom. The machines will thus always have the same electromotive force
notwithstanding variations in the speed of the engines. The means for regulating
the electromotive force may be used separately from the other part of the
Invention
Figure 7. is a perspective view of a portion of the cut off mechanisms of two
engines showing a modified arrangement of the devices for communicating motion
to the common controlling shaft, and:
Figure 8 is a sectional elevation of a portion of one of the mechanisms.
A and B represent the cut-off mechanisins of two engines which run dynamo, or
magneto electric machines, feeding into the same conductors, and having means for
regulating them as hereinbefore described.
The shaft a of each engine has a loose eccentric, which may be in one part, but
is preferably in two parts b, c, as shown. The eccentric sleeve d is connected with
the valve rod C. The fly-wheel of each engine (not shown) has weights e, f,
pivoted thereto, and thrown inwardly towards the shaft by springs g. Secured to
the shaft a near the weights e, f, are arms h, in which are pivoted bell crank levers i,
connected with the weights, and with a sleeve E feathered upon the shaft a.
sleeve has a grooved collar k with which engages the forked end of a pivoted
lever F. At its other end the lever F, is connected removably with an arm
projecting from a shaft G.
This
The cut-off mechanisms of all the engines are connected with the shaft G in a
similar manner, so that when the governor of any engine acts upon the eccentric of
such engine to adjust the same, it will also act through the intervention of the
bell-crank lever i, sleeve E, lever F and arm 7, upon the shaft G and influence the
governors of all the other engines, and thus all the engines will be forced to work
in unison.
Although the Invention is especially intended. to be applied to multiple arc
arrangements of electrical generators yet it is equally applicable when such
generators are placed in series, all feeding into the same main conductors. For
here the same difficulty exists, as should one machine give a higher electromotive
force than another, the latter will be converted into a motor, and the same
irregularities will occur as in the multiple arc arrangement.
If desired the armatures of several machines may be placed on the shaft of each
engine, or, by belts or other gearing several machines may be connected with each
engine, or two or more engines may be used to operate each battery of generators,
all the machines feeding into the same main conductors, and the engines being
regulated as herein before described.
In short the Invention is applicable to any arrangement wherein dynamo or
magneto electric machines are operated by separate sources of motive-power, without

page_text: regard to whether the electrical generators are divided into lots of one or more, or
to whether each source of motive power is composed of one or more engines.
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 herein before in part
recited Letters Patent is :-
First. The combination of two or more separate motors, a mechanism connecting
their throttle or cut-off valves and causing them to work in unison, two or more
dynamo or magneto electric machines operated by such motors, and feeding into the
same conductors, and means controlled by the speed of each motor and com.
pensating for variations in speed for maintaining constantly the electromotive force
for which the machine or machines operated by the motor is or are adjusted
substantially as hereinbefore described.
Second. The combination of a number of dynamo or magneto electric machines
operated by two or more separate motors, and feeding into the same conductors, of
means for varying the electromotive force of the machines as required by the
addition and removal of translating devices; and means controlled by the speed of
each motor and compensating for variations in speed, for maintaining constantly the
electromotive force for which the machine or machines operated by the motor is or
are adjusted substantially as herein before described.
In witness whereof I the said Thomas John Handford have hereunto set my
hand and seal this thirty first day of. March in the year of our Lord one
thousand eight hundred and eighty three.
TH J HANDFORD (L.S.)