IMPROVE- MENTS IN OR RELATING TO SYSTEMS OF ELECTRICAL DISTRIBUTION, AND APPARATUS OR MEANS FOR REGULATING THE CURRENT IN SUCH SYSTEMS
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 IN OR RELATING TO SYSTEMS OF ELECTRICAL DISTRIBUTION, AND
APPARATUS OR MEANS FOR REGULATING THE CURRENT IN SUCH SYSTEMS
"3
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 14th October 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS IN OR RELATING TO SYSTEMS OF
ELECTRICAL DISTRIBUTION
CURRENT IN BUCH SYSTEMS
募
AND APPARATUS OR MEANS FOR REGULATING THE
a communication to me from abroad by Thomas
Alva Edison of Menlo Park in the State of New Jersey United States of
America
In a system of electric lighting in which a Town or village or a portion thereof
is supplied from one central station it is generally the case that in some parts of
the district more lights are used and consequently more electricity required than
in others making an irregular arrangement of translating devices.
The object of this invention is to so arrange the system of conductors supplying
the district that the supply in the various localities of the district will be propor-
tioned to the demand and so that all the lamps throughout the district will have
practically the same candle power all being within two or three candle power of a
standard
The manner in which it has been heretofore proposed to arrange the conductors
in what is known as the Edison system of electrical distribution is as follows
videlicit: Along each face of each block in the district are laid two conductors one
positive" the other "negative" and at every street crossing where the conductors
intersect each other all the positive conductors are connected together and all the
negative are likewise connected together. That is to say: wherever two conductors
D

page_text: having currents of the same polarity cross each other they are connected together;
and feeding conductors connect with these street mains at certain definite and
regularly arranged points so that a constant amount of electricity is supplied in all
parts of the district in a uniform manner.
In carrying out the present Invention however when the district has an irregular
arrangement of lamps so that some parts of it require more current than others
the arrangement before referred to of the conductors is modified in the following
manner videlicit :-
By estimating the number of lamps or other translating devices used in the
entire district and the proportion used in various parts thereof what may be
termed the centres of consumption are discovered that is to say: the points in the
neighbourhood of which or around which a certain amount of electricity is
consumed.
In parts of the district which are thickly settled and contain many consumers
of electricity the centre of consumption would be the centre of a very small space
while in sparsely inhabited localities where few lamps are used the space surrounding
the centre of consumption would be larger. The district might thus be considered
as divided into irregularly shaped sub districts each containing about the same
number of lamps and each consuming approximately the same amount of energy.
To each of these centres of consumption is run from the central station a
feeding circuit consisting of a positive and a negative conductor each of which
is connected at the proper point to a similar conductor of the main system.
As stated above all the positive and all the negative main conductors are
connected together wherever they intersect.
It is sometimes found desirable to connect them also at other points by running
cross connections across the street at various places along the faces of the blocks
in order to maintain a uniform electromotive force.
The feeding and other conductors are preferably copper rods or bars placed in
pairs in iron tubes and surrounded and separated from the tubes and from each
other by suitable washers and by a filling of insulating material.
Small additional wires are laid in the tubes which contain the feeding conductors
forming additional circuits each of which is connected with the outer ends of the
feeders and runs from a centre of consumption back to the central station where
it passes through any suitable device for indicating electrical pressure and thence
returns to the centre of consumption so that the electrical potential at a centre of
consumption is indicated; and adjustable resistances are placed in each feeding
circuit so that according to these indications more or less current may be supplied
to the circuit.
The main conductors of the consumption circuit are made of such size that the
drop in electro-motive force upon them will not be sufficient to vary practically
the candle power of the lamps (the difference not being greater than two or three
candle power) while upon the feeding conductors any drop may be provided for
without effecting the relative candle power of the lamps of the consumption
circuit such feeding conductors having no translating devices connected therewith.
The loss upon the feeding conductors is preferably greater than that upon the main
conductors of the consumption circuit but will be varied in different localities
according to the relative cost of copper for conducting purposes and horse-power
for generation.
As above stated the "pressure" at the centres of consumption is regulated by
varying the resistance of the feeding circuits leading thereto.
Each dynamo or magneto electric machine of the battery of such machines
supplying the feeding circuits is regulated for the total number of translating
devices in circuit in any suitable way, preferably by throwing resistance into and
out of its field circuit while the adjustable resistances in the feeder circuits are used
to regulate for the unequal distribution throughout the system (the variations in
location of translating devices) without reference to the total number of translating
devices in circuit. For the purpose of varying the resistance of the feeder

page_text: "calorimeter barrels " consisting of coils of wire immersed in water and provided
with connections running to contact points and an arm for throwing more or less
of the coils into circuit may be used but it is preferred to use for this purpose
the following apparatus.
Each feeding circuit is caused to be broken at a convenient point and a number
of paths for the current are provided across such break, each of considerable
resistance, means being provided for throwing into circuit more or less of such
paths as desired. Such paths or resistances it will be understood are in multiple
are relation to each other and consequently as more are placed in circuit, the less
becomes the resistance of the feeder and the greater the amount of current supplied
to the lamps.
It is usually customary to vary the resistance of a circuit by throwing more or
less resistance in series so to speak directly into such circuit. The mode just
described is preferable however for here as fast as the resistance is decreased and
the current thereby increased in the circuit, the current carrying capacity of this
portion of the circuit is correspondingly increased.
The form of apparatus which it is preferred to employ for this purpose is the
following
=
The wire or cable from one pole of the generator or generators is connected to
one of two metal pipes preferably of copper which are placed preferably one above
the other or in any convenient position. The conductor from the other pole is
connected directly to the feeding circuit while the return conductor of such circuit
is connected with the second pipe. It is to be understood that each feeding circuit
of the district is provided with the apparatus described.
To the lower pipe are attached at short distances apart and along its entire
length in any suitable manner the ends of carbon rods the other end of each of
which is connected with the lower end of a spring whose upper end approaches
nearly to but does not touch the upper pipe.
Preferably a number of these carbon rods are placed in series between the lower
pipe and each spring.
Pivoted at one end to the frame which supports the pipes is a "Knife" consisting
of a suitable back and handle of insulating material with a copper plate or blade
such blade being preferably broad at its outer end and narrow near the handle
The knife is so placed that the blade can be forced down between the upper pipo
and the springs and make electrical connection between them; more or less of the
springs being in contact with the pipe according as the blade is pressed down or
drawn up.
It is evident that as more springs are connected with the pipe more of the
carbon rods will be placed in multiple arc between the pipes and consequently the
greater will be the conductivity of the feeding circuit of which such pipes form a
part.
Therefore when more translating devices are placed in the consumption circuit
in the vicinity of the point of connection between the feeder and such circuit the
blade is pushed down and more of the rods are thrown into circuit and when such
devices are removed from circuit the blade is raised.
At one end the pipes are connected by a rubber or other tube and one pipe is
connected at its other end to a source of water supply so that a circulation of
water is kept up and the pipes are maintained in a cool condition.
A weight is attached to the knife as a counterbalance to hold it in the position in
which it is placed; or a spring or suitable friction devices may be used for this
purpose.

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
7th April 1883.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS IN OR RELATING TO SYSTEMS OF
ELECTRICAL DISTRIBUTION AND APPARATUS OR MEANS FOR REGULATING THE
CURRENT IN SUCH BYSTEMS A communication to me from abroad by Thomas
Alva Edison of Menlo Park in the State of New Jersey United States of
America
"
In a system of electric lighting in which a town, or village, or a portion thereof
is supplied from one central station, it is generally the case that in some parts of
the district more lights are used, and consequently more electricity required, than
in others, making an irregular arrangement of translating devices.
The object of this invention is to so arrange the system of conductors supplying
the district, that the supply in the various localities of the district will be
proportioned to the demand, and so that all the lamps throughout the district will
have practically the same candle power, all being within two or three candle power
of a standard.
The manner in which it has been heretofore proposed to arrange the con-
ductors in what is known as the Edison system of electrical distribution is as
follows. vis:
Along each face of each block in the district are laid two conductors one
positive" the other "negative" and at every street crossing where the conductors
intersect each other all the positive conductors are connected together, and all the
negative. That is to say wherever two conductors having currents of the same
polarity cross each other they are connected together; and feeding conductors
connect with these street mains at certain definite and regularly arranged points,
so that a constant amount of electricity is supplied in all parts of the district in a
uniform manner.
In carrying out the present Invention however when the district has an irregular
arrangement of lamps so that some parts of it require more current than others
the arrangement before referred to of the conductors is modified in the following
manner vis:-
By estimating the number of lamps or other translating devices used in the
entire district, and the proportion used in various parts thereof, what may be termed
the centres of consumption are discovered, that is to say the points in the
neighbourhood of which or around which a certain amount of electricity is
consumed
In parts of the district which are thickly settled and contain many consumers of
electricity the centre of consumption would be the centre of a very small space,
while in sparsely inhabited localities where few lamps are used the space
surrounding the centre of consumption would be larger. The district might thus
be considered as divided into irregularly shaped sub-districts each containing
about the same number of lamps, and each consuming approximately the same
amount of energy.
To each of these centres of consumption is run from the central station a
"feeding" circuit.consisting of a positive and a negative conductor each of which
is connected at the proper point to a similar conductor of the main system.
As stated above all the positive and all the negative main conductors are
connected together wherever they intersect. It is sometimes found desirable to

page_text: connect them also at other points by running cross connections across the street at
various places along the faces of the blocks in order to maintain a uniform electro-
motive force.
The feeding and other conductors are preferably copper rods or bars placed in
pairs in iron tubes and surrounded and separated from the tubes, and from each
other by suitable washers, and by a filling of insulating material. Small additional
wires are laid in the tubes which contain the feeding conductors, forming additional
circuits each of which is connected with the outer ends of the feeders and runs
from a centre of consumption back to the central station where it passes through
any suitable device for indicating electrical pressure, and thence returns to the
centre of consumption, so that the electrical potential at a centre of consumption
is indicated; and adjustable resistances are placed in each feeding circuit so that
according to these indications more or less current may be supplied to the circuit.
The main conductors of the consumption circuit are made of such size that the
drop in electromotive force upon them will not be sufficient to vary practically the
candle power of the lamps (the difference not being greater than two or three
candle power) while upon the feeding conductors any drop may be provided for
without affecting the relative candle power of the lamps of the consumption
circuit such feeding conductors having no translating devices connected therewith.
The loss upon the feeding conductors is preferably greater than that upon the
main conductors of the consumption circuit but will be varied in different localities
according to the relative cost of copper for conducting purposes, and horse power
for generation. As above stated the "pressure at the centres of consumption is
regulated by varying the resistance of the feeding circuits leading thereto.
Each dynamo or magneto electric machine of the battery of such machines
supplying the feeding circuits is regulated for the total number of translating
devices in circuit, in any suitable way, preferably by throwing resistance into and
out of its field circuit, whilst the adjustable resistances in the feeder circuits are
used to regulate for the unequal distribution throughout the system (the variations in
location of translating devices) without reference to the total number of translating
devices in circuit. For the purpose of varying the resistance of the feeder,
"calorimeter barrels" consisting of coils of wire immersed in water, and provided
with connections running to contact points, and an arm for throwing more or less
of the coils into circuit may be used; but it is preferred to use for this purpose the
following apparatus. Each feeding circuit is caused to be broken at a convenient
point and a number of paths for the current are provided across such break, each
of considerable resistance, means being provided for throwing into circuit more or
less of such paths as desired. Such paths or resistances it will be understood are
in multiple are relation to each other, and consequently as more are placed in
circuit the less becomes the resistance of the feeder and the greater the amount of
current supplied to the lamps.
It is usually customary to vary the resistance of a circuit by throwing more or
less resistance, in series, so to speak, directly into such circuit. The mode just
described is preferable however, for here as fast as the resistance is decreased, and
the current thereby increased in the circuit, the current carrying capacity of this
portion of the circuit is correspondingly increased
The form of apparatus which it is preferred to employ for this purpose is the
following:
The wire or cable from one pole of the generator or generators is connected to
one of two metal pipes, by preference of copper, which are placed preferably one
above the other, or in any convenient position. The conductor from the other pole
is connected directly to the feeding circuit, while the return conductor of such
circuit is connected with the second pipe. It is to be understood that each feeding
circuit of the district is provided with the apparatus described.
To the lower pipe
are attached at short distances apart, and along its entire length in any suitable
manner the ends of carbon rods, the other end of each of which is connected with
the lower end of a spring whose upper end approaches nearly to, but does not

page_text: touch the upper pipe. Preferably a number of these carbon rods are placed in
series between the lower pipe and each spring. Pivoted at one end to the frame
which supports the pipes is a "knife" consisting of a suitable back and handle of
insulating material, with a copper plate or blade such blade being preferably broad
at its outer end and narrow near the handle. The knife is so placed that the blade
can be forced down between the upper pipe and the springs, and make electrical
connection between them; more or less of the springs being in contact with the
pipe according as the blade is pressed down or drawn up.
It is evident that as more springs are connected with the pipe, more of the
carbon rods will be placed in multiple arc between the pipes, and consequently the
greater will be the conductivity of the feeding circuit of which such pipes form a
part. Therefore when more translating devices are placed in the consumption circuit
in the vicinity of the point of connection between the feeder and such circuit, the
blade is pushed down, and more of the rods are thrown into circuit, and when such
devices are removed from circuit, the blade is raised.
At one end the pipes are connected by a rubber or other tube and one pipe is
connected at its other end to a source of water supply, so that a circulation of
water is kept up, and the pipes are maintained in a cool condition.
A weight is attached to the knife as a counterbalance to hold it in the position
in which it is placed; or a spring or suitable friction devices may be used for this
purpose.
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 corresponding figures.
Figure 1 is a diagram of a district showing the system of mains and feeding
circuits.
Figure 2 a diagram showing part of the district with a portion of the apparatus
used at the central station; and
Figure 3 is a cross section of one of the underground tubes containing the
conductors of a feeding circuit.
A (figure 1) represents a central station and N and P, respectively the negative
and positive poles of batteries of electric generators, situated in the station.
B, B¹, B are blocks which compose the district, or part of it.
The blocks B', B₁ may be taken as types of all the others.
In each of the streets surrounding these blocks are laid the main conductors p, n, ;
p representing positive and n, negative conductors. Wherever conductors of the
same name cross each other they are run into a junction box and connected; and
additional connections may also be made between these by cross conductors n', p',
placed across the streets at various points, along the faces of the blocks.
The centres of consumption are as before explained, various irregularly located
points at different distances from the source of supply A, such as the points
C, D, E, F. To these points are run the feeding circuits each consisting of a
positive conductor p³, and a negative conductor n³. The conductors p³, all run
from positive poles P of the generators, and the conductors n' from negative
poles N.
By these feeding circuits electricity is supplied to the different groups of lamps
each of which surrounds a centre of consumption.
In figure 3, n², p², are the feeding conductors, surrounded by insulating washer G
which separates them from an enclosing metal tube H. c, c' are small wires which
also pass through the tube H.
Figure 2 illustrates the manner in which the conductors surrounding any
block B of the district are arranged. I, I represent a battery of electric
generators; N, P, being respectively its negative and positive poles, from which
run the feeding conductors, n², p³ to the centres of consumption of the block, where
they are connected to the street conductors n, p by means of suitable junction
boxes. For convenience, in the drawing the wires c, c', which are enclosed in the

page_text: same tube with the conductors n², p² are shown separated from these conductors in
Figure 2.
These wires c, c' form an auxiliary circuit to each feeding circuit, passing
through electro-dynamometers b, b, or other suitable devices for indicating electric
pressure, situated at the central station, and which by this means indicate the
electrical potential, at the centres of consumption. d, d, are adjustable resistances
placed in the feeding circuits by means of which more or less current may be
made to pass through such circuits, according to the indications of the dynamo-
meters.
In lieu of the adjustable resistances shown in figure 2, the apparatus illustrated
in figures 4, 5, 6 and 7 and which constitutes one feature of this Invention may
be employed.
Figure 4 is a front elevation of the regulating apparatus ;
Figure 5, a transverse vertical section of the same;
Figure 6, a diagram illustrating the circuit connections; and
Figure 7 a plan of the clamp which holds the carbon rods hereinafter
described.
A, and B are two pipes filled with water and connected together by a rubber
tube C.
Referring to figure 6, a main conductor 1 from the generator or generators
represented at D, is connected to the pipe A while main conductor 2 is connected
to the conductor 3 of the feeding circuit 3, 4, this feeding circuit runs to a point
where the circuits 66' which supply the translating devices of the system are
connected to it in multiple arc. The conductor 4 of the feeding circuit is
connected to the pipe B. D¹ is an adjustable resistance in the field circuit of the
generator D.
Referring to figures 4, and 5, E is a suitable frame which supports the pipes A,
and B. a a are carbon rods having their ends held in clamps c such clamps
being preferably of the form shown in figure 7 viz: being made in two parts, ench
of which consisting of two curves joined together by a straight piece; and a
screw d, being passed through the straight portion of both, so that, a double clamp
is formed for holding two carbons. Metal pieces e are attached to the side of
pipe B, and to the other end of each a piece fis attached which enters the clamp c
whose other half holds a carbon rod. Four of these rods are shown in figure 5 as
connected in series the end of the last carbon being attached to the piece g, to
which is fastened the spring h, which approaches nearly but does not touch the
pipe A. All the pieces g are secured to the strip which is of wood or other
insulating material.
F is a copper blade, of the form shown in figure 4 attached to a suitable back G,
and having a handle H. The knife thus formed is pivoted at I, and it will be seen
can be forced down between the springs h, and the tube A, to any desired distance,
and again withdrawn, thus connecting the pipes through more or less of the
carbon rods a, a, and increasing or diminishing the conductivity of the feeding
circuit 3, 4.
The conductors are fastened to the pipes in any suitable manner.
J is a
counterbalance weight used to hold the knife in the position in which it is
placed.
Water is introduced into the pipe A by a rubber tube K and flows off through a
tube L.
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 bereinbefore in part
recited Letters Patent is :-
First In a system of electrical distribution, the combination with the inter-
secting positive and negative main conductors of feeding conductors running to
centres of consumption where they are connected to the said main conductors,

page_text: •
auxiliary circuits connected at their terminals with the terminals of the feeding
circuits, and containing a suitable device for indicating electric pressure, so that the
tension of the current at the centre of consumption is indicated, and means
located in each feeding circuit for regulating the tension of the current supplied
thereby to the consumption circuit, all substantially as herein before described.
Second: The apparatus for regulating the resistance of the feeding circuit
substantially as hereinbefore described with reference to figures 4, 5, 6 and 7 of
the accompanying drawings.
In witness whereof I the said Thomas John Handford have hereunto set
my hand and seal this sixth day of April in the year of our Lord one
thousand eight hundred and eighty three.
TH J HANDFORD (L.S.)